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CkBn6GigLOINxu289eUJw | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | For the following reaction, in the mass of water produced from 445 g of C<sub>57</sub>H<sub>110</sub>O<sub>6</sub> is :
<br/><br/>2C<sub>57</sub>H<sub>110</sub>O<sub>6</sub>(s) + 163 O<sub>2</sub>(g) $$ \to $$ 114 CO<sub>2</sub>(g) + 110 H<sub>2</sub>O(l) | [{"identifier": "A", "content": "490 g"}, {"identifier": "B", "content": "445 g"}, {"identifier": "C", "content": "495 g"}, {"identifier": "D", "content": "890 g"}] | ["C"] | null | moles of C<sub>57</sub>H<sub>110</sub>O<sub>6</sub>(s) = $${{445} \over {890}}$$ = 0.5 moles
<br><br>2C<sub>57</sub>H<sub>110</sub>O<sub>6</sub>(s) + 163 O<sub>2</sub>(g) $$ \to $$ 114 CO<sub>2</sub>(g) + 110 H<sub>2</sub>O(l)
<br><br>n<sub>H<sub>2</sub>O</sub> = $${{110} \over 4}$$ = $${{55} \over 2}$$
<br><br>m<sub>... | mcq | jee-main-2019-online-9th-january-evening-slot | 3,838 |
jQKxqaRxKFIDz7odUcYCv | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | For a reaction,<br/>
N<sub>2</sub>(g) + 3H<sub>2</sub>(g) $$ \to $$ 2NH<sub>3</sub>(g) ;<br/>
identify dihydrogen (H<sub>2</sub>) as a limiting reagent
in the following reaction mixtures. | [{"identifier": "A", "content": "56g of N<sub>2</sub> + 10g of H<sub>2</sub>"}, {"identifier": "B", "content": "14g of N<sub>2</sub> + 4g of H<sub>2</sub>"}, {"identifier": "C", "content": "28g of N<sub>2</sub> + 6g of H<sub>2</sub>"}, {"identifier": "D", "content": "35g of N<sub>2</sub> + 8g of H<sub>2</sub>"}] | ["A"] | null | Here you have to check every options to find answer.
<br><br>N<sub>2</sub>(g) + 3H<sub>2</sub>(g) $$ \to $$ 2NH<sub>3</sub>(g)
<br><br>For dihydrogen (H<sub>2</sub>) to become a limiting reagent,
<br><br>$${{moles\,of\,{H_2}} \over {stoichiometric\,coefficient\,of\,{H_2}}}$$ should be
<br><br>less than $${{moles\,of\,... | mcq | jee-main-2019-online-9th-april-morning-slot | 3,840 |
AXCOjxNdF33tuo0kru3rsa0w2w9jwvdnuf1 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | At 300 K and 1 atmospheric pressure, 10 mL of a hydrocarbon required 55 mL of O<sub>2</sub> for complete
combustion, and 40 mL of CO<sub>2</sub> is formed. The formula of the hydrocarbon is :
| [{"identifier": "A", "content": "C<sub>4</sub>H<sub>7</sub>Cl"}, {"identifier": "B", "content": "C<sub>4</sub>H<sub>6</sub>"}, {"identifier": "C", "content": "C<sub>4</sub>H<sub>8</sub>"}, {"identifier": "D", "content": "C<sub>4</sub>H<sub>10</sub>"}] | ["B"] | null | C<sub>x</sub>H<sub>y</sub> + $$\left( {x + {y \over 4}} \right)$$O<sub>2</sub> $$ \to $$ xCO<sub>2</sub> + $${y \over 2}$$H<sub>2</sub>O
<br><br>According to the above equation,
<br><br>1 mL of hydrocarbon = x mL of CO<sub>2</sub> is produced
<br><br>$$ \therefore $$ 10 mL of hydrocarbon = 10x mL of CO<sub>2</sub> is p... | mcq | jee-main-2019-online-10th-april-morning-slot | 3,841 |
DTWK2nLaP9vnWQSvio3rsa0w2w9jx83otga | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | Thermal decomposition of a Mn compound (X) at 513 K results in compound Y, MnO<sub>2</sub> and gaseous product.
MnO<sub>2</sub> reacts with NaCl and concentrated H<sub>2</sub>O<sub>4</sub> to give a pungent gas Z. X, Y and Z, respectively, are : | [{"identifier": "A", "content": "KMnO<sub>4</sub>, K<sub>2</sub>MnO<sub>4</sub> and Cl<sub>2</sub>\n"}, {"identifier": "B", "content": "K<sub>2</sub>MnO<sub>4</sub>, KMnO<sub>4</sub> and SO<sub>2</sub>"}, {"identifier": "C", "content": "K<sub>3</sub>MnO<sub>4</sub>, K<sub>2</sub>MnO<sub>4</sub> and Cl<sub>2</sub>"}, {"... | ["A"] | null | <table class="tg">
<tbody><tr>
<th class="tg-s6z2">KMnO<sub>4</sub></th>
<th class="tg-s6z2">$$\buildrel {513\,\,K} \over
\longrightarrow $$</th>
<th class="tg-s6z2">K<sub>2</sub>MnO<sub>4</sub></th>
<th class="tg-s6z2">+</th>
<th class="tg-baqh">MnO<sub>2</sub></th>
<th class="tg-baqh">+</th... | mcq | jee-main-2019-online-12th-april-evening-slot | 3,842 |
rQxfbEVfPFqzHVlQ1Qjgy2xukf9l2ky2 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | The mass of ammonia in grams produced when
2.8 kg of dinitrogen quantitatively reacts with 1
kg of dihydrogen is _______. | [] | null | 3400 | N<sub>2</sub>(g) + 3H<sub>2</sub>(g) $$ \to $$ 2NH<sub>3</sub>(g)
<br><br>Number of moles of N<sub>2</sub> = $${{2.8 \times {{10}^3}} \over {28}}$$ = 100
<br><br>Number of moles of H<sub>2</sub> = $${{1000} \over 2}$$ = 500
<br><br>Here N<sub>2</sub> is limiting reagent.
<br><br>$$ \therefore $$ Number of moles of NH<s... | integer | jee-main-2020-online-4th-september-morning-slot | 3,843 |
7CxJ6msEtaT9IeFXY0jgy2xukf2cq3xq | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | The mole fraction of glucose (C<sub>6</sub>H<sub>12</sub>O<sub>6</sub>
) in an aqueous binary solution is 0.1. The mass percentage of
water in it, to the nearest integer, is _______. | [] | null | 47 | Mole fraction of glucose in aqueous solution
= 0.1
<br><br>Let total mole is 1 mol then mole of glucose will be 0.1 and mole of water will be 0.9.
<br><br>So mass % of water = $${{0.9 \times 18} \over {0.1 \times 180 + 0.9 \times 18}}$$ $$ \times $$ 100
<br><br>= 47.37 $$ \simeq $$ 47 | integer | jee-main-2020-online-3rd-september-morning-slot | 3,844 |
2EHuNs9KnQr584kue87k9k2k5er1buo | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | The flocculation value of HCl for arsenic sulphide sol. <br/>is 30 m mol L<sup>-1</sup> If H<sub>2</sub>SO<sub>4</sub> is used for the flocculatiopn of arsenic sulphide, the amount in grams, of H<sub>2</sub>SO<sub>4</sub> in 250 ml required for the above purposed is ______.<br/>
(molecular mass of H<sub>2</sub>SO<sub>4... | [] | null | 0.36to0.38 | Arsenic sulphide sol is negatively charged, so for flocculation
positive ion required. Here positive ion H<sup>+</sup> present.
<br><br>for 1 L, 30 mm moles of H<sup>+</sup> is required
<br><br>for 250 ml, $${{30} \over 4}$$ mm moles H<sup>+</sup> is required
<br><br>$$ \therefore $$ for 250 ml, $${{30} \over {4 \time... | integer | jee-main-2020-online-7th-january-evening-slot | 3,845 |
uH6OTxcnskcV4S7LCI7k9k2k5eq1zyk | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | The ammonia (NH<sub>3</sub>) released on quantitative reaction of 0.6 g urea (NH<sub>2</sub>CONH<sub>2</sub>) with sodium hydroxide (NaOH) can be neutralized by : | [{"identifier": "A", "content": "200 ml of 0.02 N HCl"}, {"identifier": "B", "content": "100 ml of 0.2 N HCl "}, {"identifier": "C", "content": "100 ml of 0.1 HCl"}, {"identifier": "D", "content": "200 ml of 0.4 N HCl"}] | ["B"] | null | NH<sub>2</sub>CONH<sub>2</sub> $$ \to $$ NH<sub>3</sub>
<br><br>Using Principle of Atom Conservation
<br><br>2 $$ \times $$ moles of urea = 1 $$ \times $$ moles of NH<sub>3</sub>
<br><br>$$ \Rightarrow $$ 2 $$ \times $$ $${{0.6} \over {60}}$$
<br><br>$$ \Rightarrow $$ moles of NH<sub>3</sub> = 0.02
<br><br>Also moles ... | mcq | jee-main-2020-online-7th-january-evening-slot | 3,846 |
lZBtM0SzkxlslpsyLd1klrv8p1v | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | 1.86 g of aniline completely reacts to form acetanilide. 10% of the product is lost during purification. Amount of acetanilide obtained after purification (in g) is __________ $$\times$$ 10<sup>$$-$$2</sup>. | [] | null | 243 | <img src="https://app-content.cdn.examgoal.net/fly/@width/image/1kxo9dijv/33620a10-f4f0-4c1a-a705-e165d99dff9a/716b4fb0-66d8-11ec-8163-35395675f50a/file-1kxo9dijw.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1kxo9dijv/33620a10-f4f0-4c1a-a705-e165d99dff9a/716b4fb0-66d8-11ec-8163-35395675f50a/fi... | integer | jee-main-2021-online-24th-february-evening-slot | 3,848 |
9My0R4yfuhcONDZEm31kls94pra | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | Complete combustion of 1.80 g of an oxygen containing compound (C<sub>x</sub>H<sub>y</sub>O<sub>z</sub>) gave 2.64 g of CO<sub>2</sub> and 1.08 g of H<sub>2</sub>O. The percentage of oxygen in the organic compound is : | [{"identifier": "A", "content": "51.63"}, {"identifier": "B", "content": "50.33"}, {"identifier": "C", "content": "63.53"}, {"identifier": "D", "content": "53.33"}] | ["D"] | null | C<sub>x</sub>H<sub>y</sub>O<sub>z</sub> + O<sub>2</sub> $$ \to $$ xCO<sub>2</sub> + $${y \over 2}{H_2}O$$
<br><br>2.64 g of CO<sub>2</sub> contains 0.72 g C.
<br><br>1.08 g of H<sub>2</sub>O contains 0.12 g H.
<br><br>$$ \therefore $$ Mass of oxygen present = 1.80 – (0.72
+0.12) = 0.96 g
<br><br>% of O = $${{0.96} \ove... | mcq | jee-main-2021-online-25th-february-morning-slot | 3,849 |
cpvIIb4JCVFbrasaO01kmhur7jk | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | Complete combustion of 750 g of an organic compound provides 420 g of CO<sub>2</sub> and 210 g of H<sub>2</sub>O. The percentage composition of carbon and hydrogen in organic compound is 15.3 and ___________ respectively. (Round off to the Nearest Integer). | [] | null | 3 | 18 gm H<sub>2</sub>O $$ \Rightarrow $$ 2 gm H<sub>2</sub><br><br>210 gm $$ \Rightarrow $$ $${2 \over {18}} \times 210$$<br><br>= 23.33 gm H<sub>2</sub><br><br>So, % H<sub>2</sub> = $${{23.33} \over {750}} \times 100$$ = 3.11% $$ \approx $$ 3% | integer | jee-main-2021-online-16th-march-morning-shift | 3,850 |
P0mSdFAt73zFDvkBsM1kmkji9bo | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <img src="data:image/png;base64,UklGRv4PAABXRUJQVlA4IPIPAACQVwCdASo1AqAAPm02mEikIyKhIxPJeIANiWlu4W/RG/OH8Ffx/tI/sv5S/2PyK/Q/2/8rPVPrTM2H1u/AfyL+sf8L1A/zv8e8Sfdt/ZfY78gXqT/D/xL+s+VT/b/x/+u98zVP9J/YC9ifmn+K/kn9w/4n9x87/9e/iv9Z/4nuT9SP9r/GP6B8gH6f/4X+Jf179cPmr/L/5z+MeTD5l+oHwCfzf+b/5j+N/1X9T/po/R/9f/G/7B/5f73/////8Wflf/hf... | [] | null | 77 | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264365/exam_images/rjhhgvuxtxyiwi1yzjda.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 17th March Evening Shift Chemistry - Some Basic Concepts of Chemistry Question 119 English Explana... | integer | jee-main-2021-online-17th-march-evening-shift | 3,852 |
J3WgzVLVlsaMMQwdRb1kmlnvgx5 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | __________ grams of 3-Hydroxy propanal (MW = 74) must be dehydrated to produce 7.8 g of acrolein (MW = 56) (C<sub>3</sub>H<sub>4</sub>O) if the percentage yield is 64. (Round off to the Nearest Integer).<br/><br/>[Given : Atomic masses : C : 12.0 u, H : 1.0 u, O : 16.0 u ] | [] | null | 16 | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734267750/exam_images/byqxl3jhugiak03bl3a2.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 18th March Morning Shift Chemistry - Some Basic Concepts of Chemistry Question 117 English Explana... | integer | jee-main-2021-online-18th-march-morning-shift | 3,853 |
1ks1j8v5a | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | 2SO<sub>2</sub>(g) + O<sub>2</sub>(g) $$\to$$ 2SO<sub>3</sub>(g)<br/><br/>The above reaction is carried out in a vessel starting with partial pressure P<sub>SO<sub>2</sub></sub> = 250 m bar, P<sub>O<sub>2</sub></sub> = 750 m bar and P<sub>SO<sub>3</sub></sub> = 0 bar. When the reaction is complete, the total pressure i... | [] | null | 875 | 2SO<sub>2</sub>(g) + O<sub>2</sub>(g) $$\to$$ 2SO<sub>3</sub>(g)<br><br><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l2ry7os0/3e0aeb10-b629-42f4-a9e5-70bbef4f8100/02720300-cbdd-11ec-912f-ef0b3f5040a9/file-1l2ry7os1.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1l2ry7os0/3e0a... | integer | jee-main-2021-online-27th-july-evening-shift | 3,856 |
1ktecwdw1 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | In Carius method for estimation of halogens, 0.2 g of an organic compound gave 0.188 g of AgBr. The percentage of bromine in the compound is ______________. (Nearest integer)<br/><br/>[Atomic mass : Ag = 108, Br = 80] | [] | null | 40 | n<sub>AgBr</sub> = $${{0.188g} \over {188g/mol}}$$ = 10<sup>$$-$$3</sup> mol<br><br>$$\Rightarrow$$ n<sub>Br</sub> = n<sub>AgBr</sub> = 0.001 mol<br><br>$$\Rightarrow$$ mass<sub>Br</sub> = (0.001 $$\times$$ 80) gm = 0.08 gm<br><br>$$\Rightarrow$$ mass% = $${{0.08 \times 100} \over {0.2}} = 40\% $$ | integer | jee-main-2021-online-27th-august-morning-shift | 3,857 |
1l548f6vq | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>Production of iron in blast furnace follows the following equation</p>
<p>Fe<sub>3</sub>O<sub>4</sub>(s) + 4CO(g) $$\to$$ 3Fe(l) + 4CO<sub>2</sub>(g)</p>
<p>when 4.640 kg of Fe<sub>3</sub>O<sub>4</sub> and 2.520 kg of CO are allowed to react then the amount of iron (in g) produced is :</p>
<p>[Given : Molar Atomic m... | [{"identifier": "A", "content": "1400"}, {"identifier": "B", "content": "2200"}, {"identifier": "C", "content": "3360"}, {"identifier": "D", "content": "4200"}] | ["C"] | null | <p>Given,</p>
<p>Mass of $$F{e_3}{O_4}$$ = 4.640 kg = 4640 gm</p>
<p>Molar mass of $$F{e_3}{O_4}$$ = 56 $$\times$$ 3 + 16 $$\times$$ 4 = 232 g</p>
<p>$$\therefore$$ Moles of $$F{e_3}{O_4} = {{4640} \over {232}} = 20$$</p>
<p>Also, given</p>
<p>Mass of CO = 2.520 kg = 2520 gm</p>
<p>Molar mass of CO = 12 + 16 = 28 gm</p... | mcq | jee-main-2022-online-29th-june-morning-shift | 3,858 |
1l55mqyve | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>Compound A contains 8.7% Hydrogen, 74% Carbon and 17.3% Nitrogen. The molecular formula of the compound is,</p>
<p>Given : Atomic masses of C, H and N are 12, 1 and 14 amu respectively.</p>
<p>The molar mass of the compound A is 162 g mol<sup>$$-$$1</sup>.</p> | [{"identifier": "A", "content": "C<sub>4</sub>H<sub>6</sub>N<sub>2</sub>"}, {"identifier": "B", "content": "C<sub>2</sub>H<sub>3</sub>N"}, {"identifier": "C", "content": "C<sub>5</sub>H<sub>7</sub>N"}, {"identifier": "D", "content": "C<sub>10</sub>H<sub>14</sub>N<sub>2</sub>"}] | ["D"] | null | <p>Mole ratio of H, C and N</p>
<p>$$ = {{8.7} \over 1}:{{74} \over {12}}:{{17.\,3} \over {14}}$$</p>
<p>$$ = 8\,.7:6.167:1.23$$</p>
<p>$$ = {{8.7} \over {1.23}}:{{6.167} \over {1.23}}:{{1.23} \over {1.23}}$$</p>
<p>$$ = 7:5:1$$</p>
<p>$$\therefore$$ Emperical formula = $${{C_5}{H_7}N}$$</p>
<p>$$\therefore$$ Molecular... | mcq | jee-main-2022-online-28th-june-evening-shift | 3,859 |
1l55o86b5 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O' gives 0.793 g of CO<sub>2</sub> and 0.442 g of H<sub>2</sub>O. The percentage of oxygen composition in the organic compound is ______________. (nearest integer)</p> | [] | null | 46 | <p>Total organic compound = 0.492 gm</p>
<p>Produced CO<sub>2</sub> = 0.793 gm</p>
<p>$$\therefore$$ Moles of CO<sub>2</sub> = $${{0.793} \over {44}}$$</p>
<p>$$\therefore$$ Moles of C atoms = $${{0.793} \over {44}}$$</p>
<p>$$\therefore$$ Weight of C atoms = $${{0.793} \over {44}}$$ $$\times$$ 12 = 0.216 g</p>
<p>Prod... | integer | jee-main-2022-online-28th-june-evening-shift | 3,860 |
1l56ymvi1 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>116 g of a substance upon dissociation reaction, yields 7.5 g of hydrogen, 60 g of oxygen and 48.5 g of carbon. Given that the atomic masses of H, O and C are 1, 16 and 12, respectively. The data agrees with how many formulae of the following?</p>
<p>A. CH<sub>3</sub>COOH, B. HCHO, C. CH<sub>3</sub>OOCH<sub>3</sub>,... | [] | null | 2 | $$
\begin{aligned}
&\% \mathrm{H}=\frac{7.5}{116} \times 100=6.5 \\\\
&\% \mathrm{O}=\frac{60}{116} \times 100=51.7 \\\\
&\% \mathrm{C}=\frac{48.5}{116} \times 100=41.8
\end{aligned}
$$<br/><br/>
Relative atomicities $=\mathrm{H} \Rightarrow 6.5$<br/><br/>
$$
\begin{aligned}
&\mathrm{O} \Rightarrow \frac{51.7}{16}=3.25... | integer | jee-main-2022-online-27th-june-evening-shift | 3,861 |
1l58eon11 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>On complete combustion 0.30 g of an organic compound gave 0.20 g of carbon dioxide and 0.10 g of water. The percentage of carbon in the given organic compound is _____________. (Nearest integer)</p> | [] | null | 18 | <p>$${C_x}{H_y} + \left( {x + {y \over 4}} \right){O_2} \to x\,C{O_2} + {y \over 2}{H_2}O$$</p>
<p>Given organic compound C<sub>x</sub>H<sub>y</sub>= 0.3 gm</p>
<p>Produced carbon dioxide (CO<sub>2</sub>) = 0.2 gm</p>
<p>Produced water (H<sub>2</sub>O) = 0.1 gm</p>
<p>Moles of CO<sub>2</sub> = $${{0.2} \over {44}}$$</p... | integer | jee-main-2022-online-26th-june-morning-shift | 3,862 |
1l58k0v3j | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>CNG is an important transportation fuel. When 100 g CNG is mixed with 208 g oxygen in vehicles, it leads to the formation of CO<sub>2</sub> and H<sub>2</sub>O and produces large quantity of heat during this combustion, then the amount of carbon dioxide, produced in grams is ____________. [nearest integer]</p>
<p>[As... | [] | null | 143 | <p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l5mip2k4/8e8a135c-20f3-4574-aaa6-9ece3a3c64b4/0eab5f40-0445-11ed-a91d-f9384673f194/file-1l5mip2k5.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1l5mip2k4/8e8a135c-20f3-4574-aaa6-9ece3a3c64b4/0eab5f40-0445-11ed-a91d-f9384673f194... | integer | jee-main-2022-online-26th-june-evening-shift | 3,863 |
1l5amcb74 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>The number of N atoms in 681 g of C<sub>7</sub>H<sub>5</sub>N<sub>3</sub>O<sub>6</sub> is x $$\times$$ 10<sup>21</sup>. The value of x is (N<sub>A</sub> = 6.02 $$\times$$ 10<sup>23</sup> mol<sup>$$-$$1</sup>) (Nearest Integer)</p> | [] | null | 5418 | <p>Molar mass of $${C_7}{H_5}{N_3}{O_6}$$</p>
<p>= 12 $$\times$$ 7 + 5 + 14 $$\times$$ 3 + 16 $$\times$$ 6</p>
<p>= 227 gm</p>
<p>Given mass of $${C_7}{H_5}{N_3}{O_6}$$ = 681 gm</p>
<p>$$\therefore$$ Moles of $${C_7}{H_5}{N_3}{O_6}$$ $$ = {{681} \over {227}} = 3$$</p>
<p>In one molecule of $${C_7}{H_5}{N_3}{O_6}$$, 3 N... | integer | jee-main-2022-online-25th-june-morning-shift | 3,864 |
1l5bcrmoo | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>120 g of an organic compound that contains only carbon and hydrogen gives 330 g of CO<sub>2</sub> and 270 g of water on complete combustion. The percentage of carbon and hydrogen, respectively are</p> | [{"identifier": "A", "content": "25 and 75"}, {"identifier": "B", "content": "40 and 60"}, {"identifier": "C", "content": "60 and 40"}, {"identifier": "D", "content": "75 and 25"}] | ["D"] | null | <p>$${C_x}{H_y} + \left( {x + {y \over 4}} \right){O_2} \to xC{O_2} + {y \over 2}{H_2}O$$</p>
<p>From the reaction,</p>
<p>Produced CO<sub>2</sub> = x mol</p>
<p>and produced H<sub>2</sub>O = $${y \over 2}$$ mol</p>
<p>Given produced CO<sub>2</sub> = 330 g</p>
<p>$$\therefore$$ moles of CO<sub>2</sub> $$ = {{330} \over... | mcq | jee-main-2022-online-24th-june-evening-shift | 3,865 |
1l6mehn8p | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>On complete combustion of $$0.492 \mathrm{~g}$$ of an organic compound containing $$\mathrm{C}, \mathrm{H}$$ and $$\mathrm{O}$$, $$0.7938 \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$ and $$0.4428 \mathrm{~g}$$ of $$\mathrm{H}_{2} \mathrm{O}$$ was produced. The % composition of oxygen in the compound is ___________.</p> | [] | null | 46 | $\%$ of $\mathrm{H}=\frac{2}{18} \times \frac{\text { wt. of } \mathrm{H}_{2} \mathrm{O}}{\text { wt. of organic compound }} \times 100$
<br/><br/>
$$
\begin{aligned}
&=\frac{2}{18} \times \frac{0.4428}{0.492} \times 100 \\\\
&=0.11 \times 0.9 \times 100 \\\\
&=0.099 \times 100=9.9
\end{aligned}
$$
<br/><br/>
$\%$ of $... | integer | jee-main-2022-online-28th-july-morning-shift | 3,868 |
1l6p6u769 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>$$
\mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}
$$</p>
<p>$$20 \mathrm{~g} \quad ~~~5 \mathrm{~g}$$</p>
<p>Consider the above reaction, the limiting reagent of the reaction and number of moles of $$\mathrm{NH}_{3}$$ formed respectively are :</p> | [{"identifier": "A", "content": "$$\\mathrm{H}_{2}, 1.42$$ moles"}, {"identifier": "B", "content": "$$\\mathrm{H}_{2}, 0.71$$ moles"}, {"identifier": "C", "content": "$$\\mathrm{N}_{2}, 1.42$$ moles"}, {"identifier": "D", "content": "$$\\mathrm{N}_{2}, 0.71$$ moles"}] | ["C"] | null | $\underset{20 \,g}{\mathrm{N}_{2(\mathrm{~g})}}+\underset{5 \mathrm{~g}}{3 H_{2(g)}} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}$<br/><br/> Ideally $28 \mathrm{~g} \mathrm{~N}_{2}$ reacts with $6 \mathrm{~g} \,\mathrm{H}_{2}$ limiting reagent is $\mathrm{N}_{2}$<br/><br/> $\therefore$ Amount of $\mathrm{NH}_{3}$ ... | mcq | jee-main-2022-online-29th-july-morning-shift | 3,869 |
ldo82s11 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | When a hydrocarbon A undergoes complete combustion it requires 11 equivalents of oxygen and produces 4 equivalents of water. What is the molecular formula of $A$ ? | [{"identifier": "A", "content": "$\\mathrm{C}_{9} \\mathrm{H}_{8}$"}, {"identifier": "B", "content": "$\\mathrm{C}_{5} \\mathrm{H}_{8}$"}, {"identifier": "C", "content": "$\\mathrm{C}_{11} \\mathrm{H}_{4}$"}, {"identifier": "D", "content": "$\\mathrm{C}_{11} \\mathrm{H}_{8}$"}] | ["A"] | null | $$
\begin{aligned}
& \mathrm{C}_{\mathrm{x}} \mathrm{H}_{\mathrm{y}}+\left(\mathrm{x}+\frac{\mathrm{y}}{4}\right) \mathrm{O}_2 \rightarrow \mathrm{xCO}_2+\frac{\mathrm{y}}{2} \mathrm{H}_2 \mathrm{O} \\\\
& \frac{\mathrm{y}}{2}=4 \Rightarrow \mathrm{y}=8 \\\\
& \mathrm{x}+\frac{8}{4}=11 \\\\
& \Rightarrow \mathrm{x}=9 \... | mcq | jee-main-2023-online-31st-january-evening-shift | 3,870 |
ldo9rrju | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | Assume carbon burns according to the following equation :
<br/><br/>
$2 \mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow 2 \mathrm{CO}(\mathrm{g})$
<br/><br/>
when $12 \mathrm{~g}$ carbon is burnt in $48 \mathrm{~g}$ of oxygen, the volume of carbon monoxide produced is ___________ $\times 10^{-1} \math... | [] | null | 227 | <img src="https://app-content.cdn.examgoal.net/fly/@width/image/1lectiu96/0bf71257-e585-402c-b457-4e5bd7d5a743/81bc90a0-b11d-11ed-b393-e7fb130a46e6/file-1lectiu97.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1lectiu96/0bf71257-e585-402c-b457-4e5bd7d5a743/81bc90a0-b11d-11ed-b393-e7fb130a46e6/fi... | integer | jee-main-2023-online-31st-january-evening-shift | 3,871 |
1ldsch1gp | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>When a hydrocarbon A undergoes combustion in the presence of air, it requires 9.5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A?</p> | [{"identifier": "A", "content": "$$\\mathrm{C_9H_6}$$"}, {"identifier": "B", "content": "$$\\mathrm{C_6H_6}$$"}, {"identifier": "C", "content": "$$\\mathrm{C_8H_6}$$"}, {"identifier": "D", "content": "$$\\mathrm{C_9H_9}$$"}] | ["C"] | null | <p>$${C_x}{H_y} + \left( {x + {y \over 4}} \right){O_2} \to xC{O_2} + {y \over 2}{H_2}O$$</p>
<p>$${y \over 2} = 3$$</p>
<p>$$y = 6$$</p>
<p>$$x + {y \over 4} = {{19} \over 2}$$</p>
<p>$$x = {{19} \over 2} - {3 \over 2} = 8$$</p>
<p>So, formula is $${C_8}{H_6}$$.</p> | mcq | jee-main-2023-online-29th-january-evening-shift | 3,872 |
1lgq4u2eu | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>An organic compound gives $$0.220 \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$ and $$0.126 \mathrm{~g}$$ of $$\mathrm{H}_{2} \mathrm{O}$$ on complete combustion. If the $$\%$$ of carbon is 24 then the $$\%$$ of hydrogen is __________ $$\times 10^{-1}$$. ( Nearest integer)</p> | [] | null | 56 | To find the percentage of hydrogen in the compound, we first need to determine the ratio of moles of carbon and hydrogen in the products.
<br/><br/>
The moles of CO₂ produced can be calculated by dividing the mass of CO₂ produced by its molar mass (44.01 g/mol):
<br/><br/>
$$\text{moles of CO}_{2} = \frac{0.220 \,\mat... | integer | jee-main-2023-online-13th-april-morning-shift | 3,873 |
1lgszgc9k | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>The volume of hydrogen liberated at STP by treating $$2.4 \mathrm{~g}$$ of magnesium with excess of hydrochloric acid is _________ $$\times ~10^{-2} \mathrm{~L}$$</p>
<p>Given : Molar volume of gas is $$22.4 \mathrm{~L}$$ at STP.</p>
<p>Molar mass of magnesium is $$24 \mathrm{~g} \mathrm{~mol}^{-1}$$</p> | [] | null | 224 | The reaction between magnesium and hydrochloric acid is as follows :
<br/><br/>`Mg(s) + 2HCl(aq) → MgCl<sub>2</sub>(aq) + H<sub>2</sub>(g)`
<br/><br/>From the equation, we see that 1 mole of magnesium (Mg) produces 1 mole of hydrogen gas (H<sub>2</sub>).
<br/><br/>The molar mass of magnesium (Mg) is given as 24 g/m... | integer | jee-main-2023-online-11th-april-evening-shift | 3,874 |
lsapf7l1 | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | $10 \mathrm{~mL}$ of gaseous hydrocarbon on combustion gives $40 \mathrm{~mL}$ of $\mathrm{CO}_2(\mathrm{~g})$ and $50 \mathrm{~mL}$ of water vapour. Total number of carbon and hydrogen atoms in the hydrocarbon is _________ . | [] | null | 14 | <p>To solve this problem, we will use the fact that the volume ratio of gases in a reaction at the same conditions of temperature and pressure represents their mole ratio according to Avogadro's law. Thus, since the gas volumes given are at the same conditions, we can directly relate them to their stoichiometric coeffi... | integer | jee-main-2024-online-1st-february-evening-shift | 3,875 |
lsbn1xbb | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | Consider the following reaction :<br/><br/>
$$
3 \mathrm{PbCl}_2+2\left(\mathrm{NH}_4\right)_3 \mathrm{PO}_4 \rightarrow \mathrm{Pb}_3\left(\mathrm{PO}_4\right)_2+6 \mathrm{NH}_4 \mathrm{Cl}
$$
<br/><br/>
If $72 ~\mathrm{mmol}$ of $\mathrm{PbCl}_2$ is mixed with $50 ~\mathrm{mmol}$ of $\left(\mathrm{NH}_4\right)_3 \mat... | [] | null | 24 | <p>To solve this problem, we will use the stoichiometry of the balanced chemical reaction. The balanced equation shows that 3 moles of $\mathrm{PbCl}_2$ react with 2 moles of $\left(\mathrm{NH}_4\right)_3 \mathrm{PO}_4$ to produce 1 mole of $\mathrm{Pb}_3\left(\mathrm{PO}_4\right)_2$.</p>
<p>The reaction is:</p>
$$
3 ... | integer | jee-main-2024-online-1st-february-morning-shift | 3,876 |
jaoe38c1lsc6i2be | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>Mass of methane required to produce $$22 \mathrm{~g}$$ of $$\mathrm{CO}_2$$ after complete combustion is _______ g.</p>
<p>(Given Molar mass in g mol-1 $$\mathrm{C}=12.0$$, $$\mathrm{H}=1.0$$, $$\mathrm{O}=16.0)$$</p> | [] | null | 8 | <p>To solve this problem, we can use stoichiometry. First, we need to write down the balanced chemical equation for the complete combustion of methane ($$\mathrm{CH}_4$$).</p>
<p>The balanced equation for combustion of methane is:</p>
<p>$$\mathrm{CH}_4+2 \mathrm{O}_2 \rightarrow \mathrm{CO}_2+2 \mathrm{H}_2 \mathrm{... | integer | jee-main-2024-online-27th-january-morning-shift | 3,877 |
jaoe38c1lscsaedn | chemistry | some-basic-concepts-of-chemistry | quantitative-measures-in-chemical-equations | <p>$$9.3 \mathrm{~g}$$ of aniline is subjected to reaction with excess of acetic anhydride to prepare acetanilide. The mass of acetanilide produced if the reaction is $$100 \%$$ completed is _________ $$\times 10^{-1} \mathrm{~g}$$.</p>
<p>(Given molar mass in $$\mathrm{g} \mathrm{~mol}^{-1}$$</p>
<p>$$\begin{aligned}
... | [] | null | 135 | <p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1lt1oojws/578f30af-ef4e-4879-806c-11e0ae4906f5/327ec0c0-d3f5-11ee-8d6b-33dde4413c62/file-1lt1oojwt.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1lt1oojws/578f30af-ef4e-4879-806c-11e0ae4906f5/327ec0c0-d3f5-11ee-8d6b-33dde4413c62... | integer | jee-main-2024-online-27th-january-evening-shift | 3,878 |
hYqevOCAiii2rg8Scm1klue7yct | chemistry | some-basic-concepts-of-chemistry | significant-figures | The number of significant figures in 50000.020 $$\times$$ 10<sup>$$-$$3</sup> is _____________. | [] | null | 8 | 10<sup>$$-$$3</sup> has no role in significant digits. Here in 50000.020, Number of significant figure = 8 as all zeroes between non zero digits are counted as significant digits and also the last zero is also significant digit as zeroes at the end or right of the number is significant only if they are present at the ... | integer | jee-main-2021-online-26th-february-morning-slot | 3,881 |
1krxc8puf | chemistry | some-basic-concepts-of-chemistry | significant-figures | The number of significant figures in 0.00340 is ____________. | [] | null | 3 | Number of significant figures = 3 | integer | jee-main-2021-online-25th-july-evening-shift | 3,882 |
1l54xxyaf | chemistry | some-basic-concepts-of-chemistry | significant-figures | <p>Using the rules for significant figures, the correct answer for the expression $${{0.02858 \times 0.112} \over {0.5702}}$$ will be</p> | [{"identifier": "A", "content": "0.005613"}, {"identifier": "B", "content": "0.00561"}, {"identifier": "C", "content": "0.0056"}, {"identifier": "D", "content": "0.006"}] | ["B"] | null | <p>$${{0.02858 \times 0.112} \over {0.5702}}$$ = 0.00561</p>
<p>Reported answer should not be more precise than
least precise term (0.112 is the least precise term with three significant figures) in calculations, so there should
be three significant figures in reported answer.</p> | mcq | jee-main-2022-online-29th-june-evening-shift | 3,883 |
1lgyrudyw | chemistry | some-basic-concepts-of-chemistry | significant-figures | <p>Which of the following have same number of significant figures?</p>
<p>A. 0.00253</p>
<p>B. 1.0003</p>
<p>C. 15.0</p>
<p>D. 163</p>
<p>Choose the correct answer from the options given below</p> | [{"identifier": "A", "content": "A, C and D only"}, {"identifier": "B", "content": "B and C only"}, {"identifier": "C", "content": "A, B and C only"}, {"identifier": "D", "content": "C and D only"}] | ["A"] | null | <p>Significant figures are the digits in a number that carry meaningful information about its precision. In other words, they are the numbers that are known with certainty.</p>
<p>Here is how we calculate significant figures for each number:</p>
<ul>
<li><p>A. 0.00253: There are 3 significant figures here (253). Leadin... | mcq | jee-main-2023-online-8th-april-evening-shift | 3,884 |
ymXe0k7U7wjsSKup | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | In a hydrogen atom, if energy of an electron in ground state is -13.6 eV, then that in the 2<sup>nd</sup> excited state is | [{"identifier": "A", "content": "-1.51 eV"}, {"identifier": "B", "content": "-3.4 eV"}, {"identifier": "C", "content": "-6.04 eV"}, {"identifier": "D", "content": "-13.6 eV"}] | ["A"] | null | n = 1 means ground state<br><br>
n = 2 means 1<sup>st</sup> excited state<br><br>
n = 3 means 2<sup>nd</sup> excited state<br><br>
<b>Remember:</b> n<sup>th</sup> excited state means n = n + 1 <br><br>
We know energy of an atom is given by<br><br>
Energy (E) = -13.6 $$\times$$ $${{{Z^2}} \over {{n^2}}}$$<br><br>
= -13.... | mcq | aieee-2002 | 3,885 |
YfCCyH3qbhXF71wz | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen | [{"identifier": "A", "content": "5 $$\\to$$ 2"}, {"identifier": "B", "content": "4 $$\\to$$ 1"}, {"identifier": "C", "content": "2 $$\\to$$ 5"}, {"identifier": "D", "content": "3 $$\\to$$ 2"}] | ["A"] | null | In Bohr series of lines of hydrogen spectrum :-
<img class="question-image" src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734265272/exam_images/z9jbmvhqmo6lrjecf1wo.webp" loading="lazy" alt="AIEEE 2003 Chemistry - Structure of Atom Question 170 English Explanation">
Red end means end of visible region which ... | mcq | aieee-2003 | 3,886 |
fN8JlmJoUrdP6sZC | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | According to Bohr's theory, the angular momentum of an electron in 5<sup>th</sup> orbit is | [{"identifier": "A", "content": "10 $$h/\\pi$$"}, {"identifier": "B", "content": "2.5 $$h/\\pi$$"}, {"identifier": "C", "content": "25 $$h/\\pi$$"}, {"identifier": "D", "content": "1.0 $$h/\\pi$$"}] | ["B"] | null | Formula of angular momentum of an electron,
<br><br>mvr = $${{nh} \over {2\pi }}$$
<br><br>here n = 5
<br><br>$$\therefore$$ mvr = $${{5h} \over {2\pi }}$$ = 2.5$${{h} \over {\pi }}$$ | mcq | aieee-2006 | 3,887 |
41Mk8gx8RiId53bS | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | Ionisation energy of He<sup>+</sup> is 19.6 x 10<sup>–18</sup> J atom<sup>–1</sup>. The energy of the first stationary state (n = 1) of Li<sup>2+</sup> is | [{"identifier": "A", "content": "4.41 x 10<sup>\u201316</sup> J atom<sup>\u20131</sup>"}, {"identifier": "B", "content": "-4.41 x 10<sup>\u201317</sup> J atom<sup>\u20131</sup>"}, {"identifier": "C", "content": "-2.2 x 10<sup>\u201315</sup> J atom<sup>\u20131</sup>"}, {"identifier": "D", "content": "8.82 x 10<sup>\u201... | ["B"] | null | Ionisation energy(IE) - It is the energy required to move an electron from ground state to infinity.
<br><br>IE = $${E_\infty } - {E_1}$$ = $$0 - {E_1}$$ = $$ - {E_1}$$
<br><br>$$\therefore$$ E<sub>1</sub> of He<sup>+</sup> = - 19.6 x 10<sup>–18</sup> J atom<sup>–1</sup>
<br><br>Energy of a species at n state,
<br><b... | mcq | aieee-2010 | 3,888 |
SFHuJUfQ4CoAgsX9 | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | The radius of the second Bohr orbit for hydrogen atom is:<br/>
(Planck’s Const. h = 6.6262 × 10<sup>-34</sup> Js; mass of electron = 9.1091 × 10<sup>-31</sup> kg; charge of electron (e) = 1.60210 × 10<sup>-19</sup> C; permittivity of vacuum ($${\varepsilon _0}$$) = 8.854185 × 10<sup>-12</sup> kg<sup>-1</sup> m<sup>-3</... | [{"identifier": "A", "content": "4.76 $$\\mathop {\\rm A}\\limits^o $$"}, {"identifier": "B", "content": "2.12 $$\\mathop {\\rm A}\\limits^o $$"}, {"identifier": "C", "content": "0.529 $$\\mathop {\\rm A}\\limits^o $$"}, {"identifier": "D", "content": "1.65 $$\\mathop {\\rm A}\\limits^o $$"}] | ["B"] | null | Radius of an atom in n<sup>th</sup> orbit,
<br><br>r<sub>n</sub> = 0.529 $$ \times {{{n^2}} \over Z}$$
<br><br>Here n = 2
<br><br>and for hydrogen atom, atomic number (Z) = 1
<br><br>$$\therefore$$ r<sub>2</sub> = 0.529$$ \times {{{2^2}} \over 1}$$ = 2.12 $$\mathop {\rm A}\limits^o $$ | mcq | jee-main-2017-offline | 3,890 |
TLXQBgxVy537DaLdQpWjW | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | The de-Broglie's wavelength of electron present in first Bohr orbit of 'H' atom is : | [{"identifier": "A", "content": "0.529 $$\\mathop {\\rm A}\\limits^ \\circ $$"}, {"identifier": "B", "content": "2$$\\pi $$ $$ \\times $$ 0.529 $$\\mathop {\\rm A}\\limits^ \\circ $$"}, {"identifier": "C", "content": "$${{0.529} \\over {2\\pi }}$$ $$\\mathop {\\rm A}\\limits^ \\circ $$"}, {"identifier": "D", "conten... | ["B"] | null | Radius r = 0.529 $$ \times $$ $${{{n^2}} \over z}$$
<br><br>In first Bohr orbit of hydrogen atom radius,
<br><br>r = 0.529 $$ \times $$ $${{{1^2}} \over 1}$$ = 0.529 $$\mathop A\limits^ \circ $$
<br><br>Angular momentum,
<br><br>mvr = $${{nh} \over {2\pi }}$$
<br><br>$$\therefore\,\,\,$$ for  ... | mcq | jee-main-2018-online-15th-april-evening-slot | 3,891 |
YFCJMi4HwnR7wlzI5D7k9k2k5hlkh7l | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | The radius of the second Bohr orbit, in terms
of the Bohr radius, a<sub>0</sub>, in Li<sup>2+</sup> is : | [{"identifier": "A", "content": "$${{2{a_0}} \\over 9}$$"}, {"identifier": "B", "content": "$${{2{a_0}} \\over 3}$$"}, {"identifier": "C", "content": "$${{4{a_0}} \\over 9}$$"}, {"identifier": "D", "content": "$${{4{a_0}} \\over 3}$$"}] | ["D"] | null | $${r_n} = {{{n^2}{a_0}} \over Z}$$
<br><br>For 2<sup>nd</sup> Bohr orbit of Li<sup>+2</sup>
<br><br>n = 2
<br><br>and Z = 3
<br><br>r = $${{{2^2}{a_0}} \over 3}$$ = $${{4{a_0}} \over 3}$$ | mcq | jee-main-2020-online-8th-january-evening-slot | 3,892 |
3VRO6j8pYWnflYX7SB7k9k2k5idnuac | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | The de Broglie wavelength of an electron in the
4th Bohr orbit is : | [{"identifier": "A", "content": "2$$\\pi $$a<sub>0</sub>"}, {"identifier": "B", "content": "6$$\\pi $$a<sub>0</sub>"}, {"identifier": "C", "content": "8$$\\pi $$a<sub>0</sub>"}, {"identifier": "D", "content": "4$$\\pi $$a<sub>0</sub>"}] | ["C"] | null | According to Bohr’s model
<br><br>$${r_n} = {{{n^2}} \over Z} \times {a_0}$$
<br><br>Also 2$$\pi $$$${r_n}$$ = n$$\lambda $$
<br><br>$$ \Rightarrow $$ 2$$\pi $$$${{{n^2}} \over Z} \times {a_0}$$ = n$$\lambda $$
<br><br>$$ \Rightarrow $$ $$\lambda $$ = $$2\pi \times {n \over Z} \times {a_0}$$
<br><br>For n = 4 and Z = ... | mcq | jee-main-2020-online-9th-january-morning-slot | 3,893 |
2TIo7Ul2JGlOG2qGN41klru1lo0 | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | According to Bohr's atomic theory :<br/><br/>(A) Kinetic energy of electron is $$ \propto {{{Z^2}} \over {{n^2}}}$$.<br/><br/>(B) The product of velocity (v) of electron and principal quantum number (n), $$'vn' \propto {Z^2}$$.<br/><br/>(C) Frequency of revolution of electron in an orbit is $$ \propto {{{Z^3}} \over {{... | [{"identifier": "A", "content": "(A), (C) and (D) only"}, {"identifier": "B", "content": "(A) only"}, {"identifier": "C", "content": "(C) only"}, {"identifier": "D", "content": "(A) and (D) only"}] | ["D"] | null | According to Bohr's theory,<br/><br/>I. $$KE \propto {{{Z^2}} \over {{n^2}}}$$ or $$13.6 \propto {{{Z^2}} \over {{n^2}}}{{(eV)} \over {(atom)'}}$$<br/><br/> ($$\therefore$$ Correct)<br/><br/>II. Speed of electron $$ \propto {Z \over n}$$<br/><br/>(Here, Z = atomic number, n = number of shells)<br/><br/>$$\therefore$$ $... | mcq | jee-main-2021-online-24th-february-evening-slot | 3,895 |
vDX7OsXHrWn9ljlgAM1klurwqgo | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | Which of the following forms of hydrogen emits low energy $$\beta$$<sup>-</sup> particles? | [{"identifier": "A", "content": "Tritium $$_1^3$$H"}, {"identifier": "B", "content": "Proton H<sup>+</sup>"}, {"identifier": "C", "content": "Protium $$_1^1$$H"}, {"identifier": "D", "content": "Deuterium $$_1^2$$H"}] | ["A"] | null | Tritium isotope of hydrogen is radioactive and emits low energy $$\beta ^-$$ particles. It is because of high n/p ratio of tritium which makes nucleus unstable. | mcq | jee-main-2021-online-26th-february-evening-slot | 3,896 |
lv5Bovq3AsJnnksFw01kmm1a72t | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | Given below are two statements :<br/><br/>Statement I : Bohr's theory accounts for the stability and line spectrum of Li<sup>+</sup> ion.<br/><br/>Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field.<br/><br/>In the light of the above statements, choose... | [{"identifier": "A", "content": "Statement I is false but statement II is true."}, {"identifier": "B", "content": "Both statement I and statement II are true."}, {"identifier": "C", "content": "Statement I is true but statement II is false."}, {"identifier": "D", "content": "Both statement I and statement II are false.... | ["A"] | null | Bohr’s theory is applicable for unielectronic species only
Li<sup>+</sup> has two electrons.<br><br>
Bohr’s theory could not explain the splitting of
spectral lines in the presence of external magnetic
field (Zeeman effect)<br><br>
<b>Statement I</b> – false<br><br>
<b>Statement II</b> – true | mcq | jee-main-2021-online-18th-march-evening-shift | 3,897 |
1kted62a3 | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to $${{{h^2}} \over {xma_0^2}}$$. The value of 10x is ___________. (a<sub>0</sub> is radius of Bohr's orbit) (Nearest integer) [Given : $$\pi$$ = 3.14] | [] | null | 3155 | $$mvr = {{nh} \over {2\pi }}$$<br><br>$$K.E. = {{{n^2}{h^2}} \over {8{\pi ^2}m{r^2}}} = {{4{h^2}} \over {8{\pi ^2}m{{(4{a_0})}^2}}}$$<br><br>$$ = \left( {{4 \over {8{\pi ^2} \times 16}}} \right){{{h^2}} \over {ma_0^2}}$$<br><br>$$\Rightarrow$$ x = 315.507<br><br>$$\Rightarrow$$ 10x = 3155 (nearest integer) | integer | jee-main-2021-online-27th-august-morning-shift | 3,899 |
1l58ddlxi | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p>If the radius of the 3<sup>rd</sup> Bohr's orbit of hydrogen atom is r<sub>3</sub> and the radius of 4<sup>th</sup> Bohr's orbit is r<sub>4</sub>. Then :</p> | [{"identifier": "A", "content": "$${r_4} = {9 \\over {16}}{r_3}$$"}, {"identifier": "B", "content": "$${r_4} = {16 \\over {9}}{r_3}$$"}, {"identifier": "C", "content": "$${r_4} = {3 \\over {4}}{r_3}$$"}, {"identifier": "D", "content": "$${r_4} = {4 \\over {3}}{r_3}$$"}] | ["B"] | null | <p>We know,</p>
<p>$$r = {r_0} \times {{{n^2}} \over z}$$</p>
<p>For hydrogen atom,</p>
<p>$$\therefore$$ $${r_3} = {r_0} \times {{{3^2}} \over 1}$$</p>
<p>$$ \Rightarrow {r_0} \times {{{r_3}} \over 9}$$</p>
<p>and $${r_4} = {r_0} \times {{{4^2}} \over 1}$$</p>
<p>$$ = {{{r_3}} \over 9} \times 16$$</p>
<p>$$ = {{16} \o... | mcq | jee-main-2022-online-26th-june-morning-shift | 3,900 |
1l5amg261 | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p>The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is x $$\times$$ 10<sup>$$-$$8</sup> m. The value of x is ___________. (Nearest Integer).</p>
<p>(Given : Energy of the electron in the first shell of the hydrogen atom is $$-$$2.2 $$\times$$ 10<sup>$$-$$18</s... | [] | null | 4 | <p>Bohr model is not valid for lithium atom (Li) as Bohr model is valid for only single electronic species, so it would be valid for Li<sup>+2</sup> but not Li atom.
</p>
<p>So this question is <b>BONUS</b>.</p> | integer | jee-main-2022-online-25th-june-morning-shift | 3,901 |
1l6jkf94j | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p>Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.</p>
<p>Assertion A: Energy of $$2 \mathrm{s}$$ orbital of hydrogen atom is greater than that of $$2 \mathrm{s}$$ orbital of lithium.</p>
<p>Reason R: Energies of the orbitals in the same subshell decrease with incre... | [{"identifier": "A", "content": "Both A and R are true and R is the correct explanation of A."}, {"identifier": "B", "content": "Both A and R are true but R is NOT the correct explanation of A."}, {"identifier": "C", "content": "A is true but R is false."}, {"identifier": "D", "content": "A is false but R is true."}] | ["A"] | null | As the atomic number increases then the potential energy of electrons present in same shell becomes more and more negative. And therefore total energy also becomes more negative.
<br/><br/>
$$
\mathrm{E}_{\text {total }}=-13.6 \frac{\mathrm{z}^{2}}{\mathrm{n}^{2}} \mathrm{eV}
$$
<br/><br/>
$\therefore$ Energies of the ... | mcq | jee-main-2022-online-27th-july-morning-shift | 3,902 |
1l6mbuost | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p>Identify the incorrect statement from the following.</p> | [{"identifier": "A", "content": "A circular path around the nucleus in which an electron moves is proposed as Bohr's orbit."}, {"identifier": "B", "content": "An orbital is the one electron wave function $$(\\psi)$$ in an atom."}, {"identifier": "C", "content": "The existence of Bohr's orbits is supported by hydrogen s... | ["D"] | null | Atomic orbital is characterised by the quantum numbers $\mathrm{n}, l$ and $\mathrm{m}$.
<br/><br/>
Hence option D is incorrect. | mcq | jee-main-2022-online-28th-july-morning-shift | 3,903 |
1ldsdzzv8 | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p>Assume that the radius of the first Bohr orbit of hydrogen atom is 0.6 $$\mathrm{\mathop A\limits^o }$$. The radius of the third Bohr orbit of He$$^+$$ is __________ picometer. (Nearest Integer)</p> | [] | null | 270 | <p>Radius of 3<sup>rd</sup> Bohr orbit of He$$^{+3}$$</p>
<p>$$ = 0.6 \times {{{{(3)}^2}} \over 2}$$</p>
<p>$$ = 0.3 \times 9$$</p>
<p>$$ = 2.7\,\mathop A\limits^o $$</p>
<p>$$ = 270 \times {10^{ - 12}}$$ ppm</p> | integer | jee-main-2023-online-29th-january-evening-shift | 3,904 |
lgnzntql | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | Given below are two statements:
<br/><br/>
<b>Statement I</b> : According to Bohr's model of hydrogen atom, the angular momentum of an electron in a given stationary state is quantised.
<br/><br/>
<b>Statement II</b> : The concept of electron in Bohr's orbit, violates the Heisenberg uncertainty principle.
<br/><br/>
In... | [{"identifier": "A", "content": "Both Statement I and Statement II are incorrect"}, {"identifier": "B", "content": "Statement I is correct but Statement II is incorrect"}, {"identifier": "C", "content": "Both Statement I and Statement II are correct"}, {"identifier": "D", "content": "Statement I is incorrect but Statem... | ["C"] | null | Both Statement I and Statement II are correct
<br/><br/>
Statement I is correct. According to Bohr's model of the hydrogen atom, the angular momentum of an electron in a given stationary state is quantized. The angular momentum of an electron in the nth orbit is given by:
<br/><br/>
$L = n\hbar = n \frac{h}{2\pi}$
<br/... | mcq | jee-main-2023-online-15th-april-morning-shift | 3,906 |
1lgq4ogs9 | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p>The energy of an electron in the first Bohr orbit of hydrogen atom is $$-2.18 \times 10^{-18} \mathrm{~J}$$. Its energy in the third Bohr orbit is ____________.</p> | [{"identifier": "A", "content": "One third of this value"}, {"identifier": "B", "content": "Three times of this value"}, {"identifier": "C", "content": "$$\\frac{1}{9}$$ th of this value"}, {"identifier": "D", "content": "$$\\frac{1}{27}$$ of this value"}] | ["C"] | null | The energy of an electron in a hydrogen atom is given by the following formula:
<br/><br/>
$$E_n = \frac{-13.6\, \mathrm{eV}}{n^2}$$
<br/><br/>
where n is the principal quantum number (Bohr orbit number). To find the energy in the third Bohr orbit (n = 3), we can use the formula:
<br/><br/>
$$E_3 = \frac{-13.6\, \mathr... | mcq | jee-main-2023-online-13th-april-morning-shift | 3,907 |
1lgvvbcdu | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p><img src="data:image/png;base64,UklGRgoJAABXRUJQVlA4IP4IAADwggCdASoAA0EBP4HA2WW2MCynIbLJYsAwCWlu4XNBG/Pn9I2kNn32szC7f/oPGSf/8HZKIB0EEogHQQSiAdBBKIB0EEogG8y/66ozKZZJpIhl5lXnD48dvTnGhQoUKFChQoUKEcC7QP3Xnz58+fPnz58+fPnz558QdzwehhuDop3lPbsinJP7fW7irOJFu8tR09N8yS+ZHYwECnEMYraVMGQY147ags70myQxQlRymMkJadKDVFMP5oI7jggHriheC... | [] | null | 1 | <p>The energy levels of a hydrogen-like atom (such as Li²⁺ in this case) can be calculated using the formula:</p>
<p>$$E = -R_H \cdot \frac{Z^2}{n^2}$$</p>
<p>where:</p>
<ul>
<li>$E$ is the energy of the electron,</li>
<li>$R_H$ is the Rydberg constant (in joules),</li>
<li>$Z$ is the atomic number, and</li>
<li>$n$ is... | integer | jee-main-2023-online-10th-april-evening-shift | 3,908 |
lv7v4kty | chemistry | structure-of-atom | bohr's-model-for-hydrogen-atom | <p>The value of Rydberg constant $$(R_H)$$ is $$2.18 \times 10^{-18} \mathrm{~J}$$. The velocity of electron having mass $$9.1 \times 10^{-31} \mathrm{~kg}$$ in Bohr's first orbit of hydrogen atom = ________ $$\times 10^5 \mathrm{~ms}^{-1}$$ (nearest integer).</p> | [] | null | 22 | <p>$$\begin{aligned}
& \text { K.E. }=R_H \cdot \frac{z^2}{n^2}=\frac{1}{2} m v^2 \\
& v^2=\frac{2 \times 2.18 \times 10^{-18}}{9.1 \times 10^{-31}} \times \frac{1}{1}=0.479 \times 10^{13} \\
& v=21.88 \times 10^5 \mathrm{~m} / \mathrm{s}
\end{aligned}$$</p> | integer | jee-main-2024-online-5th-april-morning-shift | 3,909 |
2T7T88kQq4wEOAoG | chemistry | structure-of-atom | de-broglie-hypothesis | The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 meters per second is approximately | [{"identifier": "A", "content": "10<sup>-31</sup> meters"}, {"identifier": "B", "content": "10<sup>-16</sup> meters"}, {"identifier": "C", "content": "10<sup>-25</sup> meters"}, {"identifier": "D", "content": "10<sup>-33</sup> meters"}] | ["D"] | null | As per de-Broglie wavelength of a particle is <br><br>
Wavelength ($$\lambda $$) = $${h \over {mv}}$$<br><br>
Where h is plank's constant, m is mass of the particle and v is the velocity of the particle<br><br>
$$\therefore \lambda $$ = $${{6.63 \times {{10}^{ - 34}}} \over {0.06 \times 10}}$$<br><br>
= $${{6.63 \times... | mcq | aieee-2003 | 3,911 |
YIwlTjMeeNfhreFp | chemistry | structure-of-atom | de-broglie-hypothesis | Calculate the wavelength (in nanometer) associated with a proton moving at 1.0 x 10<sup>3</sup> ms<sup>−1</sup>
(Mass of proton = 1.67 $$\times$$ 10<sup>-27</sup> kg and h = 6.63 $$\times$$ 10<sup>-34</sup> Js) : | [{"identifier": "A", "content": "0.40 nm"}, {"identifier": "B", "content": "2.5 nm"}, {"identifier": "C", "content": "14.0 nm"}, {"identifier": "D", "content": "0.32 nm"}] | ["A"] | null | Wavelength$$\left( \lambda \right)$$ = $${h \over {mv}}$$
<br><br>= $${{6.63 \times {{10}^{ - 34}}} \over {1.67 \times {{10}^{ - 27}} \times {{10}^3}}}$$
<br><br>= 0.4 $$\times$$ 10<sup>-9</sup>
<br><br>= 0.4 nm | mcq | aieee-2009 | 3,912 |
pcBY2JhSGlhpg3gN | chemistry | structure-of-atom | de-broglie-hypothesis | The energy required to break one mole of Cl–Cl bonds in Cl<sub>2</sub> is 242 kJ mol<sup>–1</sup>. The longest
wavelength of light capable of breaking a single Cl – Cl bond is<br/>
(c = 3 x 10<sup>8</sup> ms<sup>–1</sup> and N<sub>A</sub> = 6.02 x 10<sup>23</sup> mol<sup>–1</sup>) | [{"identifier": "A", "content": "594 nm"}, {"identifier": "B", "content": "640 nm"}, {"identifier": "C", "content": "700 nm"}, {"identifier": "D", "content": "494 nm"}] | ["D"] | null | Energy required to break one Cl<sub>2</sub> molecule = $${{242 \times {{10}^3}} \over {6.02 \times {{10}^{23}}}}$$ J
<br><br>As E = $${{hc} \over \lambda }$$
<br><br>So $$\lambda = {{hc} \over E}$$
<br><br>= $${{6.626 \times {{10}^{ - 34}} \times 3 \times {{10}^8} \times 6.02 \times {{10}^{23}}} \over {242 \times {{10... | mcq | aieee-2010 | 3,913 |
1ldokr7ss | chemistry | structure-of-atom | de-broglie-hypothesis | <p>Electrons in a cathode ray tube have been emitted with a velocity of 1000 m s$$^{-1}$$. The number of following statements which is/are $$\underline {\mathrm{true}} $$ about the emitted radiation is ____________.</p>
<p>Given : $$\mathrm{h=6\times10^{-34}~J~s,m_e=9\times10^{-31}~kg}$$.</p>
<p>(A) The de-Broglie wave... | [] | null | 2 | The number of true statements about the emitted radiation is 2, i.e. statements (A) and (C).
<br/><br/>(A) is True: The de-Broglie wavelength of an electron can be calculated as lambda = h / p, where h is Planck's constant and p is the momentum of the electron. The momentum of an electron with a velocity of 1000 m/s i... | integer | jee-main-2023-online-1st-february-morning-shift | 3,915 |
lv0vytj5 | chemistry | structure-of-atom | de-broglie-hypothesis | <p>The de-Broglie's wavelength of an electron in the $$4^{\text {th }}$$ orbit is ________ $$\pi \mathrm{a}_0$$. ($$\mathrm{a}_0=$$ Bohr's radius)</p> | [] | null | 8 | <p>The de-Broglie wavelength of an electron can be expressed through its relationship with the principal quantum number $$n$$ in a Bohr orbit. According to de Broglie, the wavelength $ \lambda $ of an electron moving in an orbit can be related to its momentum. However, when considering an electron in an atom, specifica... | integer | jee-main-2024-online-4th-april-morning-shift | 3,917 |
lvc57i6o | chemistry | structure-of-atom | de-broglie-hypothesis | <p>Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is _________ $$\times 10^{13} \mathrm{~Hz}$$ (nearest integer).</p>
<p>[Given : $$\mathrm{R}_{\mathrm{H}}$$ (Rydberg constant) $$=2.18 \times 10^{-18} \mathrm{~J}, h$$ (Plank's constant) $$=6.6 \times 10^{-34} \mathrm{~J} . \mathrm{s... | [] | null | 658 | <p>$$\begin{aligned}
& \lambda=\frac{h}{m v} \\
& \lambda \cdot v=\frac{h}{m} \\
& \frac{\lambda \cdot v^2}{v}=\frac{h}{m} \\
& \frac{v^2}{\text { Frequency }}=\frac{h}{m}
\end{aligned}$$</p>
<p>$$\begin{aligned}
& \text { Frequency }=\frac{\mathrm{mv}^2}{\mathrm{~h}}=\frac{2 \mathrm{R}_{\mathrm{H}}}{\mathrm{h}} \\
& =... | integer | jee-main-2024-online-6th-april-morning-shift | 3,918 |
RSUl17B4KTBkfgsW | chemistry | structure-of-atom | electronic-configuration-and-nodes | Which one of the following groupings represents a collection of isoelectronic species? (At. nos. : Cs : 55, Br : 35) | [{"identifier": "A", "content": "N<sup>3-</sup>, F<sup>-</sup>, Na<sup>+</sup>"}, {"identifier": "B", "content": "Be, Al<sup>3+</sup>, Cl<sup>-</sup>"}, {"identifier": "C", "content": "Ca<sup>2+</sup>, Cs<sup>+</sup>, Br "}, {"identifier": "D", "content": "Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>"}] | ["A"] | null | Isoelectronic means those species whose electron number are same.<br><br>
<style type="text/css">
.tg {width: 100%;border-collapse:collapse;border-spacing:0;border:none;border-color:#999;}
.tg td{font-family:Arial, sans-serif;font-size:14px;padding:10px 5px;border-style:solid;border-width:0px;overflow:hidden;word-brea... | mcq | aieee-2003 | 3,919 |
bH46VJtbNLYxFGQo | chemistry | structure-of-atom | electronic-configuration-and-nodes | Of the following sets which one does NOT contain isoelectronic species? | [{"identifier": "A", "content": "$$BO_3^{3 - }$$, $$CO_3^{2 - }$$, $$NO_3^{- }$$"}, {"identifier": "B", "content": "$$SO_3^{2 - }$$, $$CO_3^{2 - }$$, $$NO_3^{-}$$"}, {"identifier": "C", "content": "$$CN^{- }$$, $$N_2$$, $$C_2^{2 - }$$"}, {"identifier": "D", "content": "$$PO_4^{3 - }$$, $$SO_4^{2 - }$$, $$ClO_4^{ - }$$"... | ["B"] | null | In $$SO_3^{2 - }$$ no of electrons = 16 + 24 + 2 = 42
<br><br>In $$CO_3^{2 - }$$ no of electrons = 6 + 24 + 2 = 32
<br><br>In $$NO_3^{-}$$ no of electrons = 7 + 24 + 1 = 32
<br><br>So they are not isoelectronic. | mcq | aieee-2005 | 3,921 |
fYZaue5XeCAA7xbI | chemistry | structure-of-atom | electronic-configuration-and-nodes | Pick out the isoelectronic structure from the following :
<br/><br/>$$\eqalign{
& \left( i \right)\,\,\,\,\,\,C{H_3}^ + \cr
& \left( {ii} \right)\,\,\,\,{H_3}{O^ + } \cr
& \left( {iii} \right)\,\,\,N{H_3} \cr
& \left( {iv} \right)\,\,\,\,C{H_3}^ - \cr} $$ | [{"identifier": "A", "content": "$$(i)$$ and $$(ii)$$ "}, {"identifier": "B", "content": "$$(iii)$$ and $$(iv)$$ "}, {"identifier": "C", "content": "$$(i)$$ and $$(iii)$$ "}, {"identifier": "D", "content": "$$(ii), (iii)$$ and $$(iv)$$ "}] | ["D"] | null | <table class="tg">
<tbody><tr>
<th class="tg-de48">Ions </th>
<th class="tg-de48">No. of electrons</th>
</tr>
<tr>
<td class="tg-wv9z">CH<sub>3</sub><sup>+</sup></td>
<td class="tg-wv9z">8</td>
</tr>
<tr>
<td class="tg-wv9z">H<sub>3</sub>O<sup>+</sup></td>
<td class="tg-wv9z">10</td>
... | mcq | aieee-2005 | 3,922 |
b03gVgWuXmI3qC22 | chemistry | structure-of-atom | electronic-configuration-and-nodes | Which of the following sets of ions represents a collection of isoelectronic species? | [{"identifier": "A", "content": "N<sup>3-</sup>, O<sup>2-</sup>, F<sup>-</sup>, S<sup>2-</sup>"}, {"identifier": "B", "content": "Li<sup>+</sup>, Na<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>"}, {"identifier": "C", "content": "K<sup>+</sup>, Cl<sup>-</sup>, Ca<sup>2+</sup>, Sc<sup>3+</sup>"}, {"identifier": "D", "co... | ["C"] | null | Option $$(c)$$ is correct.
<br><br>In $$\,\,{K^ + }\left( {19} \right)\,\,$$ no. of electrons
<br><br>$$ = 19 - 1\,\,\,\,\, = 18$$
<br><br>In $$\,\,{Cl^ - }\left( {17} \right)\,\,$$ no. of electrons
<br><br>$$ = 17 + 1\,\,\,\,\, = 18$$
<br><br>In $$\,\,{Ca^ 2+ }\left( {20} \right)\,\,$$ no. of electrons
<br><br>$$ ... | mcq | aieee-2006 | 3,923 |
o6mA6AxOKuOKG4zP | chemistry | structure-of-atom | electronic-configuration-and-nodes | Which one of the following constitutes a group of the isoelectronic species? | [{"identifier": "A", "content": "$$C_2^{2 - }$$, $$O_2^{-}$$, CO, NO"}, {"identifier": "B", "content": "$$NO^{+}$$, $$C_2^{2 - }$$, CN<sup>-</sup>, $$N_2$$"}, {"identifier": "C", "content": "CN<sup>-</sup>, $$N_2$$, $$O_2^{2-}$$, $$C_2^{2 - }$$"}, {"identifier": "D", "content": "$$N_2$$, $$O_2^{-}$$, $$NO^{+}$$, CO"}] | ["B"] | null | <table class="tg">
<tbody><tr>
<th class="tg-de48">Species</th>
<th class="tg-de48">No. of electrons</th>
</tr>
<tr>
<td class="tg-pjk9">C<sub>2</sub><sup>2-</sup></td>
<td class="tg-pjk9">12+2 = 14</td>
</tr>
<tr>
<td class="tg-pjk9">O<sub>2</sub><sup>-</sup></td>
<td class="tg-pjk9">... | mcq | aieee-2008 | 3,924 |
1t8KnCesGIAARFRIeC3rsa0w2w9jwup40cd | chemistry | structure-of-atom | electronic-configuration-and-nodes | The isoelectronic set of ions is : | [{"identifier": "A", "content": "F<sup>\u2013</sup>, Li<sup>+</sup>, Na<sup>+</sup> and Mg<sup>2+ </sup>"}, {"identifier": "B", "content": "Li<sup>+</sup>, Na<sup>+</sup>, O<sup>2-</sup> and F<sup>- </sup>"}, {"identifier": "C", "content": "N<sup>3\u2013</sup>, O<sup>2-</sup>, F<sup>-</sup> and Na<sup>+ </sup>"}, {"ide... | ["C"] | null | Atomic numbers of N, O, F and Na are 7, 8, 9
and 11 respectively.
<br><br>Therefore, total number of
electrons in each of N<sup>3-</sup>, O<sup>2–</sup>, F<sup>–</sup> and Na<sup>+</sup> is 10
and hence they are isoelectronic. | mcq | jee-main-2019-online-10th-april-morning-slot | 3,926 |
SeaEfsy2zg9A1eKiRe3rsa0w2w9jx55b0hl | chemistry | structure-of-atom | electronic-configuration-and-nodes | The group number, number of valence electrons, and valency of an element with atomic number 15,
respectively, are: | [{"identifier": "A", "content": "16, 6 and 3\n"}, {"identifier": "B", "content": "15, 6 and 12"}, {"identifier": "C", "content": "16, 5 and 2"}, {"identifier": "D", "content": "15, 5 and 3"}] | ["D"] | null | P[15] = [Ne] 3s<sup>2</sup>3p<sup>3</sup>
<br><br>Group number = 10 + valance shell electron = 10 + 5 = 15
<br><br>number of valence electrons = 5
<br><br>Valency = 3 | mcq | jee-main-2019-online-12th-april-morning-slot | 3,927 |
S92kk16mmQYeosX0RP7k9k2k5hltccg | chemistry | structure-of-atom | electronic-configuration-and-nodes | Hydrogen has three isotopes (A), (B) and (C).
If the number of neutron(s) in (A), (B) and (C)
respectively, are (x), (y) and (z), the sum of (x),
(y) an (z) is : | [{"identifier": "A", "content": "3"}, {"identifier": "B", "content": "1"}, {"identifier": "C", "content": "4"}, {"identifier": "D", "content": "2"}] | ["A"] | null | Hydrogen has three isotopes
<br><br>(A) Protium ($${}_1^1H$$) has 0 neutron.
<br><br>(B) Deutrium ($${}_1^2H$$) has 1 neutrons.
<br><br>(C) Tritium ($${}_1^3H$$) has 2 neutrons.
<br><br>Total number of neutrons in three <br>isotopes of
hydrogen = 0 + 1 + 2 = 3 | mcq | jee-main-2020-online-8th-january-evening-slot | 3,928 |
LJ3LhuwhcNFrYDYDsE1klue0c5x | chemistry | structure-of-atom | electronic-configuration-and-nodes | The orbital having two radial as well as two angular nodes is : | [{"identifier": "A", "content": "3p"}, {"identifier": "B", "content": "5d"}, {"identifier": "C", "content": "4d"}, {"identifier": "D", "content": "4f"}] | ["B"] | null | Number of radial nodes = (n – l – 1)<br><br>
Number of angular nodes = l<br><br>
for 5d; n = 5, l = 2<br><br>
5d orbital has two radial nodes and two angular nodes | mcq | jee-main-2021-online-26th-february-morning-slot | 3,929 |
3zMNrAgCzdvti0g1yJ1kmln1oy5 | chemistry | structure-of-atom | electronic-configuration-and-nodes | A certain orbital has no angular nodes and two radial nodes. The orbital is : | [{"identifier": "A", "content": "2s"}, {"identifier": "B", "content": "3s"}, {"identifier": "C", "content": "3p"}, {"identifier": "D", "content": "2p"}] | ["B"] | null | Angular nodes = $$\ell $$ = 0<br><br>
Radial nodes $$ \Rightarrow $$ (n – $$\ell $$ – 1) = 2<br>
$$ \Rightarrow $$ n – 0 – 1 = 2<br>
$$ \Rightarrow $$ n = 3<br><br>
So orbital is 3s. | mcq | jee-main-2021-online-18th-march-morning-shift | 3,930 |
1l58iscjf | chemistry | structure-of-atom | electronic-configuration-and-nodes | <p>The number of radial and angular nodes in 4d orbital are, respectively</p> | [{"identifier": "A", "content": " 1 and 2"}, {"identifier": "B", "content": "3 and 2"}, {"identifier": "C", "content": "1 and 0"}, {"identifier": "D", "content": "2 and 1"}] | ["A"] | null | <p>We know,</p>
<p>Radial nodes = n $$-$$ l $$-$$ 1</p>
<p>and Angular nodes = l</p>
<p>For 4d orbital,</p>
<p>n = 4</p>
<p>l = 2</p>
<p>$$\therefore$$ Radial nodes = 4 $$-$$ 2 $$-$$ 1 = 1</p>
<p>Angular nodes = 2</p> | mcq | jee-main-2022-online-26th-june-evening-shift | 3,932 |
1l5alobsw | chemistry | structure-of-atom | electronic-configuration-and-nodes | <p>The pair, in which ions are isoelectronic with AI<sup>3+</sup> is :</p> | [{"identifier": "A", "content": "Br<sup>$$-$$</sup> and Be<sup>2+</sup>"}, {"identifier": "B", "content": "Cl<sup>$$-$$</sup> and Li<sup>+</sup>"}, {"identifier": "C", "content": "S<sup>2$$-$$</sup> and K<sup>+</sup>"}, {"identifier": "D", "content": "O<sup>2$$-$$</sup> and Mg<sup>2+</sup>"}] | ["D"] | null | O<sup>2–</sup>, Mg<sup>2+</sup> and Al<sup>3+</sup> are isoelectronic. All have 10 electrons. | mcq | jee-main-2022-online-25th-june-morning-shift | 3,933 |
1l6i62hpp | chemistry | structure-of-atom | electronic-configuration-and-nodes | <p>Consider an imaginary ion $${ }_{22}^{48} \mathrm{X}^{3-}$$. The nucleus contains '$$a$$'% more neutrons than the number of electrons in the ion. The value of 'a' is _______________. [nearest integer]</p> | [] | null | 4 | Number of electrons in $${ }_{22}^{48} X^{3-}$$ is 25 .
<br/><br/>
Number of neutrons $$=48-22=26$$.
<br/><br/>
$$\%$$ increase in the number of neutrons over electrons
<br/><br/>
$$
=\left(\frac{26-25}{25}\right) 100=4 \%
$$
<br/><br/>
$$\therefore a=4$$ | integer | jee-main-2022-online-26th-july-evening-shift | 3,934 |
1l6kpdcns | chemistry | structure-of-atom | electronic-configuration-and-nodes | <p>Outermost electronic configurations of four elements A, B, C, D are given below :</p>
<p>(A) $$3 s^{2}$$</p>
<p>(B) $$3 s^{2} 3 p^{1}$$</p>
<p>(C) $$3 s^{2} 3 p^{3}$$</p>
<p>(D) $$3 s^{2} 3 p^{4}$$</p>
<p>The correct order of first ionization enthalpy for them is :</p> | [{"identifier": "A", "content": "(A) < (B) < (C) < (D)"}, {"identifier": "B", "content": "(B) < (A) < (D) < (C)"}, {"identifier": "C", "content": "(B) < (D) < (A) < (C)"}, {"identifier": "D", "content": "(B) < (A) < (C) < (D)"}] | ["B"] | null | Orbitals with fully filled and half-filled electronic configuration are stable, and require more energy for ionization
<br/><br/>
Elements with greater electronegativity require more energy for ionisation
<br/><br/>
Hence the correct order is $C>D>A>B$ | mcq | jee-main-2022-online-27th-july-evening-shift | 3,935 |
1ldwschva | chemistry | structure-of-atom | electronic-configuration-and-nodes | <p>The number of s-electrons present in an ion with 55 protons in its unipositive state is</p> | [{"identifier": "A", "content": "10"}, {"identifier": "B", "content": "9"}, {"identifier": "C", "content": "12"}, {"identifier": "D", "content": "8"}] | ["A"] | null | The number of protons in an element determines its atomic number, which is the number of electrons in a neutral atom of the element. The unipositive state of an ion indicates that it has lost one electron. Therefore, the number of electrons in a unipositive ion is one less than the atomic number.<br/><br/>
The element ... | mcq | jee-main-2023-online-24th-january-evening-shift | 3,937 |
lgo0jkav | chemistry | structure-of-atom | electronic-configuration-and-nodes | The total number of isoelectronic species from the given set is ___________.<br/><br/>
$\mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{Al}, \mathrm{Mg}^{2+}, \mathrm{Na}^{+}, \mathrm{O}^{+}, \mathrm{Mg}, \mathrm{Al}^{3+}, \mathrm{F}$ | [] | null | 5 | Isoelectronic species are atoms, ions or molecules that have the same number of electrons. To find the isoelectronic species from the given set, we need to determine the number of electrons in each species.
<br/><br/>
The electron configuration of each species is:
<br/><br/>
- $\mathrm{O}^{2-}$: $1s^2\ 2s^2\ 2p^6$, 10 ... | integer | jee-main-2023-online-15th-april-morning-shift | 3,938 |
1lgyt4cpt | chemistry | structure-of-atom | electronic-configuration-and-nodes | <p>The number of atomic orbitals from the following having 5 radial nodes is ___________.</p>
<p>$$7 \mathrm{s}, 7 \mathrm{p}, 6 \mathrm{s}, 8 \mathrm{p}, 8 \mathrm{d}$$</p> | [] | null | 3 | <p>Radial nodes in an atomic orbital are areas where the probability of finding an electron is zero. The number of radial nodes in an orbital is given by the formula: </p>
<p>$ \text{number of radial nodes} = n - l - 1 $</p>
<p>where $n$ is the principal quantum number and $l$ is the azimuthal quantum number. The azimu... | integer | jee-main-2023-online-8th-april-evening-shift | 3,939 |
lsaotnb3 | chemistry | structure-of-atom | electronic-configuration-and-nodes | The number of radial node/s for $3 p$ orbital is : | [{"identifier": "A", "content": "3"}, {"identifier": "B", "content": "2"}, {"identifier": "C", "content": "1"}, {"identifier": "D", "content": "4"}] | ["C"] | null | <p>The number of radial nodes in an orbital is given by the formula:</p>
<p>$$
\text{Number of radial nodes} = n - l - 1
$$</p>
<p>where
$$n$$ is the principal quantum number,
$$l$$ is the azimuthal quantum number also known as the angular momentum quantum number.</p>
<p>For a $$3p$$ orbital,
<br/><br/>$$n = 3$$ (sin... | mcq | jee-main-2024-online-1st-february-evening-shift | 3,940 |
YisqRgD5VJowdT8d | chemistry | structure-of-atom | heisenberg-uncertainty-principle | Uncertainty in position of a minute particle of mass 25 g in space is 10<sup>-5</sup> m. What is the uncertainty in its velocity (in ms<sup>-1</sup>) (h = 6.6 $$\times$$ 10<sup>-34</sup> Js) | [{"identifier": "A", "content": "2.4 $$\\times$$ 10<sup>-34</sup>"}, {"identifier": "B", "content": "0.5 $$\\times$$ 10<sup>-34</sup>"}, {"identifier": "C", "content": "2.1 $$\\times$$ 10<sup>-28</sup>"}, {"identifier": "D", "content": "0.5 $$\\times$$ 10<sup>-23</sup>"}] | ["C"] | null | According to Hysenberg's Uncertainty Principal
$$$\Delta x . \Delta p \ge { h \over {4\pi}}$$$
Where $$\Delta x $$ is uncertainty in position and $$\Delta p $$ is uncertainty in momentum and as in momentum m (mass of object) is always same so we can say
$$$\Delta x . m. \Delta v \ge { h \over {4\pi}}$$$
Mass of the par... | mcq | aieee-2002 | 3,941 |
5KsHu1M3tbccJ0lG | chemistry | structure-of-atom | heisenberg-uncertainty-principle | Uncertainty in the position of an electron (mass = 9.1 $$\times$$ 10<sup>-31</sup> kg) moving with a velocity 300 ms<sup>-1</sup>, accurate upto 0.001% will be (h = 6.63 $$\times$$ 10<sup>-34</sup> Js) | [{"identifier": "A", "content": "1.92 $$\\times$$ 10<sup>-2</sup> m"}, {"identifier": "B", "content": "3.84 $$\\times$$ 10<sup>-2</sup> m"}, {"identifier": "C", "content": "19.2 $$\\times$$ 10<sup>-2</sup> m"}, {"identifier": "D", "content": "5.76 $$\\times$$ 10<sup>-2</sup> m"}] | ["A"] | null | % error in velocity = $${{\Delta V} \over V} \times 100$$
<br><br>$$ \therefore $$ 0.001 = $${{\Delta V} \over {300}} \times 100$$
<br><br>$$ \Rightarrow $$ $$\Delta $$V = 3 $$ \times $$ 10<sup>-3</sup>
<br><br>According to Heisenberg uncertainty principle,
<br><br>$$\Delta x.m\Delta V \ge {h \over {4\pi }}$$
<br><br>$... | mcq | aieee-2006 | 3,942 |
EfIY5anToRCUDjzF | chemistry | structure-of-atom | heisenberg-uncertainty-principle | In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainity
with which the position of the electron can be located is (h = 6.6 $$\times$$ 10<sup>-34</sup> kg m<sup>2</sup>s<sup>-1</sup>, mass of electron, e<sub>m</sub> = 9.1 $$\times$$ 10<sup>-31</sup> kg) | [{"identifier": "A", "content": "5.10 $$\\times$$ 10<sup>-3</sup> m"}, {"identifier": "B", "content": "1.92 $$\\times$$ 10<sup>-3</sup> m"}, {"identifier": "C", "content": "3.84 $$\\times$$ 10<sup>-3</sup> m"}, {"identifier": "D", "content": "1.52 $$\\times$$ 10<sup>-4</sup> m"}] | ["B"] | null | % error in velocity = $${{\Delta V} \over V} \times 100$$
<br><br>$$ \therefore $$ 0.005 = $${{\Delta V} \over {600}} \times 100$$
<br><br>$$ \Rightarrow $$ $$\Delta $$V = 3 $$ \times $$ 10<sup>-2</sup>
<br><br>According to Heisenberg uncertainty principle,
<br><br>$$\Delta x.m\Delta V \ge {h \over {4\pi }}$$
<br><br>$... | mcq | aieee-2009 | 3,943 |
CcmYX28UPLaltVcd0f1klut5r7h | chemistry | structure-of-atom | heisenberg-uncertainty-principle | A ball weighing 10 g is moving with a velocity of 90 ms<sup>$$-$$1</sup>. If the uncertainty in its velocity is 5%, then the uncertainty in its position is ___________ $$\times$$ 10<sup>$$-$$33</sup> m. (Rounded off to the nearest integer)<br/><br/>[Given : h = 6.63 $$\times$$ 10<sup>$$-$$34</sup> Js] | [] | null | 1 | m = 10 g = 10<sup>$$-$$2</sup> Kg<br><br>v = 90 m/sec.<br><br>$$\Delta$$ = v $$\times$$ 5% = 90 $$\times$$ $${5 \over {100}}$$ = 4.5 m/sec<br><br>m . $$\Delta$$v . $$\Delta$$x $$ \ge $$ $${h \over {4\pi }}$$<br><br>10<sup>$$-$$2</sup> $$\times$$ 4.5 $$\times$$ $$\Delta$$x $$ \ge $$ $${{6.63 \times 3 \times {{10}^{ - 34... | integer | jee-main-2021-online-26th-february-evening-slot | 3,944 |
1krxbtjgb | chemistry | structure-of-atom | heisenberg-uncertainty-principle | An accelerated electron has a speed of 5 $$\times$$ 10<sup>6</sup> ms<sup>$$-$$1</sup> with an uncertainty of 0.02%. The uncertainty in finding its location while in motion is x $$\times$$ 10<sup>$$-$$9</sup> m. The value of x is ____________. (Nearest integer)<br/><br/>[Use mass of electron = 9.1 $$\times$$ 10<sup>$$-... | [] | null | 58 | $$\Delta v = {{0.02} \over {100}} \times 5 \times {10^6} = {10^3}$$ m/s<br><br>$$\Delta x.\Delta v = {h \over {4\pi m}}$$<br><br>$$ \Rightarrow $$ $$x \times {10^{ - 9}} \times {10^3} = {{6.63 \times {{10}^{ - 34}}} \over {4 \times 3.14 \times 9.1 \times {{10}^{ - 31}}}}$$<br><br>$$ \Rightarrow $$ $$x \times {10^{ - 9}... | integer | jee-main-2021-online-25th-july-evening-shift | 3,945 |
1l57svs0j | chemistry | structure-of-atom | heisenberg-uncertainty-principle | <p>If the uncertainty in velocity and position of a minute particle in space are, 2.4 $$\times$$ 10<sup>$$-$$26</sup> (m s<sup>$$-$$1</sup>) and 10<sup>$$-$$7</sup> (m) respectively. The mass of the particle in g is ____________. (Nearest integer)</p>
<p>(Given : h = 6.626 $$\times$$ 10<sup>$$-$$34</sup> Js)</p> | [] | null | 22 | <p>We know from hisenberg uncertainty principle</p>
<p>$$\Delta x\,.\,\Delta p = {h \over {4\pi }}$$</p>
<p>$$ \Rightarrow \Delta x\,.\,m\Delta v = {h \over {4\pi }}$$</p>
<p>Given, </p>
<p>$$\Delta$$x = 10<sup>$$-$$7</sup> m</p>
<p>$$\Delta$$x = 2.4 $$\times$$ 10<sup>$$-$$26</sup> m/s</p>
<p>h = 6.626 $$\times$$ 10<su... | integer | jee-main-2022-online-27th-june-morning-shift | 3,946 |
1l6p7wv24 | chemistry | structure-of-atom | heisenberg-uncertainty-principle | <p>The minimum uncertainty in the speed of an electron in an one dimensional region of length $$2 \mathrm{a}_{\mathrm{o}}$$ (Where $$\mathrm{a}_{\mathrm{o}}=$$ Bohr radius $$52.9 \,\mathrm{pm}$$) is _________ $$\mathrm{km} \,\mathrm{s}^{-1}$$.</p>
<p>(Given : Mass of electron = 9.1 $$\times$$ 10<sup>$$-$$31</sup> kg, P... | [] | null | 548 | Heisenberg's uncertainty principle
<br/>
$$
\begin{aligned}
& \Delta \mathrm{x} \times \Delta \mathrm{P}_{\mathrm{x}} \geq \frac{h}{4 \pi} \\
& \Rightarrow 2 \mathrm{a}_{0} \times \mathrm{m} \Delta \mathrm{v}_{\mathrm{x}}=\frac{h}{4 \pi} \text { (minimum) } \\
& \Rightarrow \Delta \mathrm{v}_{\mathrm{x}}=\frac{h}{4 \pi... | integer | jee-main-2022-online-29th-july-morning-shift | 3,947 |
luxzqk68 | chemistry | structure-of-atom | heisenberg-uncertainty-principle | <p>Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter $$10^{-15} \mathrm{~m}$$ is ________ $$\times 10^9 \mathrm{~ms}^{-1}$$ (nearest integer)</p>
<p>[Given : mass of electron $$=9.1 \times 10^{-31} \mathrm{~kg}$$, Plank's consta... | [] | null | 58 | <p>To find the uncertainty in the velocity of the electron within an atomic nucleus of diameter $10^{-15} \ \text{m}$, we can use Heisenberg's uncertainty principle. The principle is expressed as:</p>
<p>$ \Delta x \cdot m \Delta v \geq \frac{h}{4 \pi} $</p>
<p>Here, $\Delta x$ is the uncertainty in position, $m$ is ... | integer | jee-main-2024-online-9th-april-evening-shift | 3,948 |
k09CJFg6NGiaTv7E | chemistry | structure-of-atom | hydrogen-spectrum | The wavelength of the radiation emitted when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097 $$\times$$ 10<sup>7</sup> m<sup>-1</sup>) | [{"identifier": "A", "content": "406 nm"}, {"identifier": "B", "content": "192 nm"}, {"identifier": "C", "content": "91 nm"}, {"identifier": "D", "content": "9.1 $$\\times$$ 10<sup>-8</sup> nm"}] | ["C"] | null | We know Rydberg formula,
<br><br>$${1 \over \lambda } = R \times {Z^2}\left( {{1 \over {n_1^2}} - {1 \over {n_2^2}}} \right)$$
<br><br>[ for hydrogen atom Z = 1 ]
<br><br> = $$1.097 \times {10^7}\left( {{1 \over {{1^2}}} - {1 \over {{\infty ^2}}}} \right)$$
<br><br>$$ \therefore $$ $$\lambd... | mcq | aieee-2004 | 3,949 |
sZWnnkK82yYmQY9U | chemistry | structure-of-atom | hydrogen-spectrum | The ionization enthalpy of hydrogen atom is 1.312 × 10<sup>6</sup> J mol<sup>−1</sup>. The energy required to excite the
electron in the atom from n = 1 to n = 2 is | [{"identifier": "A", "content": "8.51 \u00d7 10<sup>5</sup> J mol<sup>\u22121</sup>"}, {"identifier": "B", "content": "6.56 \u00d7 10<sup>5</sup> J mol<sup>\u22121</sup>"}, {"identifier": "C", "content": "7.56 \u00d7 10<sup>5</sup> J mol<sup>\u22121</sup>"}, {"identifier": "D", "content": "9.84 \u00d7 10<sup>5</sup> J ... | ["D"] | null | <b>Note :</b>
<br><br>1 eV/atom = 96.485 $$ \times $$ 10<sup>3</sup> J/mol
<br><br>$$\therefore$$ 13.6 eV/atom = 13.6$$ \times $$ 96.485 $$ \times $$ 10<sup>3</sup> J/mol = 1.312 × 10<sup>6</sup> J mol<sup>−1</sup>
<br><br>Energy required to excite the electron from n<sub>1</sub> to n<sub>2</sub> is
<br><br>$$\Delta E ... | mcq | aieee-2008 | 3,950 |
EJfaZP3w13VOJxuS | chemistry | structure-of-atom | hydrogen-spectrum | Energy of an electron is given by $$E = - 2.178 \times {10^{ - 18}}J\left( {{{{Z^2}} \over {{n^2}}}} \right)$$. Wavelength of light required to excite an
electron in an hydrogen atom from level n = 1 to n = 2 will be<br/>
(h = 6.62 × 10<sup>−34</sup> Js and c = 3.0 × 10<sup>8</sup> ms<sup>−1</sup>) | [{"identifier": "A", "content": "2.816 \u00d7 10<sup>\u22127</sup> m "}, {"identifier": "B", "content": "6.500 \u00d7 10<sup>\u22127</sup> m"}, {"identifier": "C", "content": "8.500 \u00d7 10<sup>\u22127</sup> m"}, {"identifier": "D", "content": "1.214 \u00d7 10<sup>\u22127</sup> m"}] | ["D"] | null | Given $$E$$ = $$- 2.178 \times {10^{ - 18}}J\left( {{{{Z^2}} \over {{n^2}}}} \right)$$
<br> = $$ - 2.178 \times {10^{ - 8}}{Z^2}\left( {{1 \over {n_2^2}} - {1 \over {n_1^2}}} \right)$$
<br>Electron in an hydrogen atom exited from... | mcq | jee-main-2013-offline | 3,951 |
YOSc4PhWSUSbPu2OX8wQV | chemistry | structure-of-atom | hydrogen-spectrum | If the shortest wavelength in Lyman series of hydrogen atom is A, then the longestwavelength in Paschen series of He<sup>+</sup> is : | [{"identifier": "A", "content": "$${{5A} \\over 9}$$"}, {"identifier": "B", "content": "$${{9A} \\over 5}$$"}, {"identifier": "C", "content": "$${{36A} \\over 5}$$"}, {"identifier": "D", "content": "$${{36A} \\over 7}$$"}] | ["D"] | null | <b><u>Note</u> :</b>
<br><br>(1) In Lyman Series, transition happens in n = 1 state
<br>from n = 2, 3, . . . . . $$ \propto $$
<br><br>(2) In Balmer Series, transition happens in n = 2 state
<br>from n = 3, 4, . . . . . $$ \propto $$
<br><br>(3) In Paschen Series, ... | mcq | jee-main-2017-online-8th-april-morning-slot | 3,952 |
3kSEPthQdGxIdpC6YFNq7 | chemistry | structure-of-atom | hydrogen-spectrum | The electron in the hydrogen atom undergoes transition from higher orbitals
to orbital of radius 211.6 pm. This transition is associated with : | [{"identifier": "A", "content": "Lyman series"}, {"identifier": "B", "content": "Balmer series"}, {"identifier": "C", "content": "Paschen series"}, {"identifier": "D", "content": "Brackett series"}] | ["B"] | null | Here electron is coming to the orbital of radius 211.6 pm. Now we have to find which series have radius of orbital 211.6 pm.
<br><br>We know,
<br><br>Radius, r = $$0.529 \times {{{n^2}} \over Z}\,\mathop A\limits^ \circ $$
<br><br>Given, r = 211.6 pm = 211.6 $$ \times $$ 10<sup>-12</sup> m
<br><br>and Z = 1 for hydrog... | mcq | jee-main-2017-online-9th-april-morning-slot | 3,953 |
U946F4N0kaJUMwhd46fSu | chemistry | structure-of-atom | hydrogen-spectrum | For emission line of atomic hydrogen from n<sub>i</sub> = 8 to n<sub>f</sub> = n, the plot of wave number $$\left( {\overline v } \right)$$ against $$\left( {{1 \over {{n^2}}}} \right)$$ will be (The Rydberg constant, R<sub>H</sub> is in wave number unit) | [{"identifier": "A", "content": "Linear with intercept $$-$$R<sub>H</sub>"}, {"identifier": "B", "content": "Non linear "}, {"identifier": "C", "content": "Linear with slope R<sub>H</sub>"}, {"identifier": "D", "content": "Linear with slope $$-$$R<sub>H</sub>"}] | ["C"] | null | We know,
<br><br>$$\overline v = {1 \over \lambda } = {R_H}{Z^2}\left[ {{1 \over {n_f^2}} - {1 \over {n_i^2}}} \right]$$
<br><br>here n<sub>i</sub> $$=$$ 8 and n<sub>f</sub> $$=$$ n
<br><br>Z $$=$$ 1 for hydrogen
<br><br>$$ \therefore $$ $$\overline v = {1 \over \lambda } = {R_H}\left[ {{1 \over {{n... | mcq | jee-main-2019-online-9th-january-morning-slot | 3,954 |
9se8wYIKEPrvyjqeqlSv2 | chemistry | structure-of-atom | hydrogen-spectrum | The ground state energy of hydrogen atom is – 13.6 eV. The energy of second excited state of He<sup>+</sup> ion in eV is : | [{"identifier": "A", "content": "$$-$$ 6.04"}, {"identifier": "B", "content": "$$-$$ 54.4"}, {"identifier": "C", "content": "$$-$$ 27.2"}, {"identifier": "D", "content": "$$-$$ 3.4"}] | ["A"] | null | (E)<sub>n<sup>th</sup></sub> = (E<sub>GND</sub>)<sub>H</sub> . $${{{Z^2}} \over {{n^2}}}$$
<br><br>E<sub>3<sup>rd</sup></sub> (He<sup>+</sup>) = ($$-$$13.6eV) . $${{{2^2}} \over {{3^2}}}$$ = $$-$$ 6.04 eV | mcq | jee-main-2019-online-10th-january-evening-slot | 3,955 |
QvCzsZ8ob1PHF1Ojjy15Q | chemistry | structure-of-atom | hydrogen-spectrum | Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this purpose?
<br/><br/>[R<sub>H</sub> = 1 $$ \times $$ 10<sup>5</sup> cm<sup>–1</sup>, h = 6.6 $$ \times $$ 10<sup>–34</sup> Js, c = 3 $$ \times $$ 10<sup>8</sup> ms<sup>–1</sup>]
| [{"identifier": "A", "content": "Balmer, $$\\infty $$ $$ \\to $$ 2 "}, {"identifier": "B", "content": "Paschen, 5 $$ \\to $$ 3 "}, {"identifier": "C", "content": "Paschen, $$\\infty $$ $$ \\to $$ 3"}, {"identifier": "D", "content": "Lyman, $$\\infty $$ $$ \\to $$ 1"}] | ["C"] | null | Given, R<sub>H</sub> = 1 $$ \times $$ 10<sup>5</sup> cm<sup>–1</sup>
<br><br>$$ \Rightarrow $$ $${1 \over {{R_H}}}$$ = 10<sup>-5</sup> cm
<br><br>$$ \Rightarrow $$ $${1 \over {{R_H}}}$$ = 10<sup>-7</sup> cm $$ \times $$ 100
<br><br>$$ \Rightarrow $$ $${1 \over {{R_H}}}$$ = 100 nm
<br><br>We know,
<br><br>$${1 \over \la... | mcq | jee-main-2019-online-11th-january-morning-slot | 3,956 |
NmFzi45N1bd5Rwlmme3rsa0w2w9jx0wvawz | chemistry | structure-of-atom | hydrogen-spectrum | The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The
spectral series are : | [{"identifier": "A", "content": "Paschen and Pfund"}, {"identifier": "B", "content": "Balmer and Brackett"}, {"identifier": "C", "content": "Lyman and Paschen"}, {"identifier": "D", "content": "Brackett and Pfund"}] | ["C"] | null | Shortest wavelength can found when n<sub>2</sub> = $$\infty $$
<br><br>$${\lambda _{shortest}} = R{Z^2}\left\{ {{1 \over {n_1^2}} - {1 \over {{\infty ^2}}}} \right\}$$
<br><br>Here n<sub>1</sub> = series number.
<br><br>$$ \Rightarrow $$$${\lambda _{shortest}} =$$ $${{{R{Z^2}} \over {n_1^2}}}$$ = $${{{R{{\left( 1 \righ... | mcq | jee-main-2019-online-10th-april-evening-slot | 3,958 |
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