instruction stringlengths 15 21.8k |
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1. $\frac{0.214g}{0.428g} = \frac {x}{0.782g}$
2. Your answer is ok, but on an exam you want to solve quickly.
2.710g - 1.451g = ?
wasn't that easier?
3.
>35.967(0.00006) + 37.962(x) + 39.962(1-x) = 39.948
This is slightly wrong.
0.00006, x, 0.99994-x |
I am dealing with the iodine clock reaction, which has the half-reactions:
$$\begin{align}&\ce{H_2O_2 (aq) + 2I^- (aq) \to I_2 (s) + 2 OH^- (aq)} & (slow) \\ &\ce{I_2 (s) + 2S_2O_3^{-2} (aq) \to{} 2I^- (aq) + S_4O_6^{-2} (aq)} & (fast) \end{align}$$
Now, I have to find the rate law. What I did was 4 solutions - on... |
For most Diels-Alder reaction, the product is endo because there is favorable interactions between the newly forming pi-bond and the electron withdrawing groups of the dienophile. But why is the reaction between Furan and Maleic Anhydride an exception ? From what I understand, the carbonyl groups of the anhydride is el... |
Furan and maleic anhydride...why exo is the major product? |
If I had some NaCl dissolved in water, it is conductive, so if I were to put two electrodes in the container (powered), what is causing the flow of electrons?
Do the NaCl ionic bonds break and the ionic atoms collect at the oppositely charged electrode (how I'd assume electroplating works) with all of the atoms themsel... |
For most Diels-Alder reactions, the product is endo because there are favorable interactions between the newly forming pi-bond and the electron withdrawing groups of the dienophile.
Why is the reaction between Furan and Maleic Anhydride an exception? From what I understand, the carbonyl groups of the anhydride are ... |
Furan and maleic anhydride: Why is the major product exo? |
How does the path of light become visible due to scaterring of light ?Acc. to me it will only tell the presence of colloidal particle but the book give the example of cinema hall projector and says that you could tell path of light due to scattering of light. Nevertheless ,without scaterring of light also we can tell i... |
Why does increasing number of salt bridges increase voltage of electrochemical battery? |
I want to know that, Can I convert Toluene in to Benzoic acid, using Pyridinium Chlorochromate(PCC)?
|
Can I oxidize toluene to benzoic acid using Pyridinium Chlorochromate(PCC)? |
How does the path of light become visible due to scattering of light?
According to me it only indicates the presence of colloidal particles, but my book gives the example of a cinema hall projector and says that you could see the path of light due to its scattering. Nevertheless, it's possible to see the lights pat... |
There have been various explanations posited for the [$\alpha$-effect](http://en.wikipedia.org/wiki/Alpha_effect). It is currently in the [list of unsolved problems in chemistry](http://en.wikipedia.org/wiki/List_of_unsolved_problems_in_chemistry) on Wikipedia, but, due to a lack of references to that effect, I'm not e... |
Why does a buffer work most effectively when the concentration of salt and acid is 1:1? |
Buffer solution most effective when concentration of salt and acid same? |
Why is a buffer solution most effective when concentrations of salt and acid are the same? |
The numbers indicate which carbons the substituents - the fluorine atoms - are on. The root of the molecular name is "tetrafluoro," indicating the presence of four fluorine substituents. So now where are they? That's what the numbers tell us; the "1,1,1" part indicates that there are three fluorine substituents on the ... |
I've been making some ice cream without a ice cream maker, using salt, ice, mixer and steel canister since I can't get a ice cream machine around here and its fun. It works pretty good but it seems slower than a simple ice cream machine that uses a freezer bowl. And the freezer wall volume seems smaller than the amount... |
Will ice cream freeze faster with frozen brine or adding salt to ice? |
All of the questions involve the same reasoning, so let's look at question #2.
What is the % oxygen in $\ce{MgSO4}$ when there is no water of hydration (x=0)? It would be given by $$\ce{\%~ oxygen~ =~ \frac(4 * atomic~ wgt~ O)(atomic~wgt~ Mg + atomic~ wgt~S + (4*atomic~ wgt~ O))}$$ $$\ce{=~\frac(4*16)(24_{.}31+32+(... |
In Chemistry class, we had to combine dissolved K2Cr2O7 with 2-methyl-2-propanol and heat it for the oxitation to occure. <b>But why does it need heat, while dissolved K2Cr2O7 with for example a butanol doesn't need heat for oxidation to occure?</b> |
Why does 2-methyl-2-propanol need heat (for oxidation)? |
On skin permeability, according to Wikipedia:
"Human skin has a low permeability; that is, most foreign substances are
unable to penetrate and diffuse through the skin. Skin's outermost
layer, the stratum corneum, is an effective barrier to most inorganic
nanosized particles.[22][23]"
However there is little t... |
Skin permeability, for all chemicals or just some? |
In Chemistry class, we had to combine dissolved $\ce{K2Cr2O7}$ with 2-methyl-2-propanol and heat it for the oxidation to occur. <b>But why does it need heat, while dissolved $\ce{K2Cr2O7}$ with for example butanol doesn't need heat for oxidation to occur?</b> |
My daughter has a chemistry exam on Tuesday. She is doing quite well with her revision except for the following table which she is having difficulty remembering.
Does anyone know of an easy way to remember this? Or perhaps if someone could explain why these exceptions are insoluble that will help her instead?
![In... |
The 2nd law is
$d S \ge \displaystyle \frac{d q}{T}$
so the best you can do is zero for a reversible process. Or if you don't like inequalities,
$d S = \displaystyle \frac{d q}{T} + d S_{irr}$
where $d S_{irr}$ is the entropy production due to the irreversible processes within the system.
You can fin... |
From what I understand generally coke is carbonated to roughly 6.2g per liter in bottles and cans, or 3.1 volumes of CO2. I was watching this video because I was curious about how fountain soda machines worked.
https://www.youtube.com/watch?v=RRHNt67xbMs
By the end of the video they suggest that the soda is carb... |
From what I understand generally coke is carbonated to roughly 6.2g per liter in bottles and cans, or 3.1 volumes of CO2. I was watching this video because I was curious about how fountain soda machines worked.
https://www.youtube.com/watch?v=RRHNt67xbMs
By the end of the video they suggest that the soda is carb... |
Can the size of molecule oxygen reduce smaller? If yes, how is that possible? Is it related to proton and electron surrounding the nucleus? |
How does charge come on dispersion medium in colloidal sols ? (It is said that in electro-osmosis flow of dispersion medium takes because it is also electrically charged, but why ? ) |
If we look at the right-hand-side table here: http://en.wikipedia.org/wiki/Hammett_equation, we notice something particular. It appears that the free energy of activation (for example, measured in terms of the acidicity of a carboxyl group on a benzene ring), and with respect to substituents in the para- position on t... |
If we look at the right-hand-side table here: http://en.wikipedia.org/wiki/Hammett_equation, we notice something particular. It appears that the free energy of activation (for example, measured in terms of the acidicity of a carboxyl group on a benzene ring), and with respect to substituents in the para- position on t... |
#Toxicity of tobacco combustion products in different phases
For answering your question I think is better split it in two. First thing you need to understand that toxicity depends on **the method of administation** of the toxic agent. Tobacco smoke is a physical state of the tobacco combustion products. It is an aero... |
Understanding why it happens unfortunately will not help her to remember. This is the classic case where you have to find a dirty way to remember them. Maybe you can make some practical experiment I remember most of them with a practical application of the salts.
There are a lot of online resource regarding Mnemo... |
I saw an ad on tv last night for Mitchum deodorant that showed big text on the screen that said "OXYGEN eliminates all odors!" or something similar. Their website indeed claims ["Our exclusive formula releases pure oxygen, a powerful odor fighter..."][1].
How does oxygen fight odors, and how can this aspect of the ... |
How does oxygen fight odors? (Deodorant ad) |
I'm not a chemist, and nor do I study chemistry so please try to be gentle.
Glucose has the molecular formula $\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$ and the empirical formula $\mathrm{C}\mathrm{H}_{2}\mathrm{O}$.
Starting from the empirical formula and working the other way, am I guaranteed that $\mathrm{C}_n\... |
If I had a beaker of water (i.e. many molecules), at exactly 0°C and at atmospheric pressure, what phase would be encountered?<br/>
And would the answer to this also apply to other substances at their freezing/melting point, and out of interest, would the same effect be observed at their other "phase intercepts" too? |
If I had a beaker of water (i.e. many molecules), at exactly $0^{\circ}C$ and at atmospheric pressure, what phase would be encountered?<br/>
And would the answer to this also apply to other substances at their freezing/melting point, and out of interest, would the same effect be observed at their other "phase intercep... |
I understand how liquids can become solids by decreasing temperature. To my understanding this is because the molecules slow down and are able to form bonds.
However, I'm having problems understanding how we can create a solid out of liquid by beating it, such as the case with cream becoming butter if you beat it l... |
Can you please explain the difference between bond enthalpies in these situations? |
Enthalpy of bond S-O is stronger in SO3 or SO3^2-? |
Why is a C-Br bond considered polar? From electronegativity considerations, both carbon and bromine have very similar electronegativities - 2.5 and 2.8 - respectively.
Nonetheless, I am told that such a bond would be polar. We generally classify bond between atoms with EN differences < 0.5 as non-polar; why would C... |
My hypothesis is that the bond enthalpy of the S-O bond in the sulfate anion is smaller than that of the S-O bond enthalpy in sulfur trioxide. I would say that the S-O bond strength lies with atomic size.
In sulfate anion, we have the electronegative oxygen atoms stabilizing the bulk of the negative 2 formal charge... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/flS52.png
What does the question mean by how many electron pairs are in 2p orbitals? How does one tell? Given that both the oxygen and the nitrogen are $\ce{sp^2}$ hybridized, wouldn't there be _two_ empty 2p orbitals? |
![enter image description here][1]
What does the question mean by how many electron pairs are in 2p orbitals? How does one tell? Given that both the oxygen and the nitrogen are $\ce{sp^2}$ hybridized, wouldn't there be _two_ empty 2p orbitals?
![enter image description here][2]
[1]: https://i.stack.imgu... |
Is there any single element (e.g. possibly carbon) that can be eaten, which has nutritional value in that it provides calories? I found on Wikipedia that http://en.wikipedia.org/wiki/Dietary_element that there are certain elements that our bodies require. I suppose oxygen could count as such a nutritional element, al... |
Does any element have nutritional (caloric) value? |
![enter image description here][1]
What does the question mean by how many electron pairs are in 2p orbitals? How does one tell? Given that both the oxygen and the nitrogen are $\ce{sp^2}$ hybridized, wouldn't there be _two_ 2p orbitals?
![enter image description here][2]
[1]: https://i.stack.imgur.com/... |
The numbers indicate which carbons the substituents - the fluorine atoms - are on. The root of the molecular name is "tetrafluoro," indicating the presence of four fluorine substituents. So now where are they? That's what the numbers tell us; the "1,1,1" part indicates that there are three fluorine substituents on the ... |
I poked around on the internet and found a lot of sites use the Pauling electronegativity scale ([link 1][1], [link 2][2]). For carbon the value is 2.55 and for bromine 2.96. Not quite a 0.5 difference, but closer - and this "rule" is somewhat arbitrary to begin with. Also the dipole moment of bromobenzene is around... |
In transition metals, is the shell with the highest energy considered the valence shell? For example, in copper the electronic configuration is ${[Ar]\text{ } 3d^{10}\text{ } 4s^{1}}$. However, in accordance with the afbau principle the $3d$ subshell actually has higher energy than the $4s$ one. Does this mean the $3d$... |
I am trying to write a balanced equation for the above mentioned reaction but having some trouble figuring it out. So far, I have:
([C6H4N3O2]+ Cl-) + H2SO4 + H20 -> C6H5NO3 + N2 + ???
How do I "incorporate" sulfuric acid and water to the reaction ? Thanks for any help. |
Balanced equation for synthesis of p-nitrophenol from p-nitrodiaznoium chloride salt and sulfuric acid/water? |
I am trying to write a balanced equation for the above mentioned reaction but having some trouble figuring it out. So far, I have:
$$\ce{([C6H4N3O2]+ Cl^{-}) + H2SO4 + H2O -> C6H5NO3 + N2 + ?}$$
How do I "incorporate" sulfuric acid and water to the reaction ? Thanks for any help. |
![thiosemicarbazide][1]
[1]: https://i.stack.imgur.com/ZZ9oN.png
How to form Schiffs Base at both the ends of the thiosemicarbazide?
Nh2 of hydrazine part reacts easily to form Schiffs base i.e. imine. But NH2 attached to C=S does not. How to do that?
One approach is by using NCS but that forms imine at NH2... |
From what I understand generally coke is carbonated to roughly 6.2g per liter in bottles and cans, or 3.1 volumes of CO2. I was watching this video because I was curious about how fountain soda machines worked.
https://www.youtube.com/watch?v=RRHNt67xbMs
By the end of the video they suggest that the soda is carb... |
The question says: A proton is accelerated to one tenth of the velocity of light. If it's velocity can be measured with a precision +- 1%. What must be its uncertainty in position? <br><br>
Therefore,<br>
v=0.1c =3*10^7 m/s<br>
Delta(v)=1/100 <br>
m= 1.6*10^(-27) kg
<br><br>
Then I directly substituted these values i... |
The question says: A proton is accelerated to one tenth of the velocity of light. If it's velocity can be measured with a precision $\pm 1\%$. What must be its uncertainty in position?
Therefore,
> $v=0.1\times c =3\times 10^7 m/s\\
\Delta(v)=\frac{1}{100}\\
m= 1.6\times10^{-27} kg$
Then I directly subs... |
The question says: A proton is accelerated to one tenth of the velocity of light. If it's velocity can be measured with a precision $\pm 1\%$. What must be its uncertainty in position?
Therefore,
> $v=0.1\cdot c =3\cdot 10^7\:\mathrm{m/s}\\
\Delta(v)=\frac{1}{100}\\
m= 1.6\cdot10^{-27}\:\mathrm{kg}$
The... |
I was wondering that since acids dissociate in water to make a lot of H+ cations. Is it possible that introducing a supply of electrons via an electric current, would create H2 gas? |
Since aqueous acids release H+ into the solution, will an electric current create H2 gas? |
$dm^3$ atm is the unit of Energy. $1 dm^3 atm$ is equal to how many calories? |
I'm using a sensor that measures $\ce{CO2}$ in ppm by volume aka atmosphere.
What I'm using it for is to measure $\ce{CO2}$ concentration in water which is measured in ppm by weight.
This is what I have so far
Ppmwco2 = ppmvco2 * 0.8317 * 44.01 / 10000;
// quicker than co2/1000000 * 0.8317 * 44.01 ... |
Convert $\ce{CO2}$ ppm volume to ppm weight? |
I was wondering that since acids dissociate in water to make a lot of $\ce{H+}$ cations. Is it possible that introducing a supply of electrons via an electric current, would create $\ce{H2}$ gas? |
Since aqueous acids release $\ce{H+}$ into the solution, will an electric current create $\ce{H2}$ gas? |
Why are unpaired electrons especially reactive? Does pairing electrons decrease the reactivity of the electrons? But then doesn't forcing two electrons into the same orbital cost energy? |
Why are radicals unstable? |
What solvent would have the fewest ions? |
Does anyone know of a step by step guide to building a microbial fuel cell? Could someone here on Chem SE possibly provide one? I am looking for something like [THIS](http://www.engr.psu.edu/ce/enve/logan/bioenergy/pdf/Cathode_093008.pdf) but for the whole fuel cell and not just the cathode. |
Does anyone know of a step by step guide to building a microbial fuel cell? Could someone here on Chem SE possibly provide one? I am looking for something like [THIS](http://www.engr.psu.edu/ce/enve/logan/bioenergy/pdf/Cathode_093008.pdf) but for the whole fuel cell and not just the cathode.
Descriptive papers on th... |
In which of the following chemical compounds are the building blocks molecules?
> - $(A) AgNO_{3}$
> - $(B) HNO_{3}$
> - $(C) KNO_{3}$
> - $(D) NaNO_{3}$
**B** is the correct answer, but I have no idea why. Could you briefly explain why this is the correct answer?
Thank you in advance. |
In which of the following chemical compounds are the building blocks molecules? |
In which of the following chemical compounds are the building blocks molecules?
> (A) $\ce{AgNO3}$
> (B) $\ce{HNO3}$
> (C) $\ce{KNO3}$
> (D) $\ce{NaNO3}$
(B) is the correct answer, but I have no idea why. Could you briefly explain why this is the correct answer?
|
Since aqueous acids release Hydrogen cations into the solution, will an electric current create Hydrogen gas? |
Convert CO₂ ppm volume to ppm weight? |
Why do NaHCO₃ and KHCO₃ have different crystal structures? |
The unit of energy, 1 dm³ atm, is equal to how many calories? |
What do '(6S)' and '5' mean in (6S)-5-formyltetrahydrofolate? |
$m(FeSO_{4} \cdot x H_{2}O)=20.0g$
$N(H_{2}O)=3.03 \cdot10^{23}$
----------
$x=?$
What I've done:
**(1.)**
> $m (H_{2}O)= \frac{N(H_{2}O) \cdot M(H_{2}O)}{N_{A}}$
> $m (H_{2}O)= \frac{3.03 \cdot10^{23} \cdot 18.02g/mol}{6.02 \cdot 10^{23}/mol}$
>$m (H_{2}O)= 9.06987g$
**(2.)**
> $m(FeSO_{4}... |
Any suggestions how to solve this? |
$m(\ce{FeSO4. $x$~H2O})=20.0\:\mathrm{g}$
$N(\ce{H2O})=3.03 \cdot10^{23}$
----------
$x=?$
What I've done:
**(1.)**
> \begin{aligned}
m (\ce{H2O})&= \frac{N(\ce{H2O}) \cdot M(\ce{H2O})}{N_{A}}\\
&= \frac{3.03 \cdot10^{23} \cdot 18.02$\:\mathrm{g/mol}}{6.02 \cdot 10^{23}/\:\mathrm{mol}}\\
&... |
Why doesn't alkaline earth metals lose only one electron when they are ionized ? I know that magnesium atoms like to have the electronic configuration of neon but I don't understand the reason that we can't find Mg+1 atoms . |
Why doesn't alkaline earth metals lose only one electron when they are ionized ? |
Is bond formation "strictly" exothermic? The IUPAC definition of exothermic doesn't make any reference to bond formation. However, I have seen the aforementioned statement before - that bond "formation" is strictly exothermic.
I suspect that the answer is "it depends" and that "it depends" at least on how accuratel... |
Is Bond Formation "Strictly" Exothermic? |
Is bond formation "strictly" exothermic? The IUPAC definition of exothermic doesn't make any reference to bond formation. However, I have seen the aforementioned statement before - that bond formation is "strictly" exothermic.
I suspect that the answer is "it depends" and that "it depends" at least on how accuratel... |
Is bond formation "strictly" exothermic? The IUPAC definition of exothermic doesn't make any reference to bond formation. However, I have seen the aforementioned statement before - that bond formation is "strictly" exothermic.
I suspect that the answer is "it depends" and that "it depends" at least on how accuratel... |
Does the hyponitrite molecule exist? I know the hyponitrite ion exists (http://en.wikipedia.org/wiki/Hyponitrite) but what about the molecule?
I have found no reference to the molecular form on Wikipedia. But it does seem that such a molecule could at least come together through the dimerization of nitric oxide. |
Why don't alkaline earth metals lose only one electron when they are ionized? |
Does evaporation of non-water liquids into the atmosphere vary with atmospheric humidity? |
I am a physicist, not a chemist. I'm trying to get a basic understanding of the reactions taking place in a battery using a saltwater electrolyte with copper and zinc terminals. I'm writing a general science level article about it. I have found that the reactions taking place at the terminals are:
Zinc terminal
$... |
I am working on a chemistry assignment and can't figure out part of the problem.
0.2 moles of a compound with a molecular weight of 82 contain 9.6g of Carbon, 1.2g of Hydrogen and the rest is Nitrogen
The question is asking for the emperical and molecular formuala which I can solve, but how do you determine the a... |
![C NMR for Benzaldehyde][1]
[1]: https://i.stack.imgur.com/guc34.gif
Assuming this image is correct, why is the Carbon-3 more deshielded than Carbon-2 and Carbon-1 ? From what I understand, deshielding is the greatest when the Carbon atom is closer to electron withdrawer and it appears Carbon-3 is the farthe... |
Benzaldehyde NMR Question? |
What happens when strongly basic water is electrolyzed? I know that the electrolysis of water in strongly acidic solution involves hydrogen protons; will these protons still be involved in strongly basic solution? |
![enter image description here][1]
[1]: https://i.stack.imgur.com/TSNET.png
Regarding the above question, how would one solve it?
Would it be valid to simply say that I know that 6 electrons are being transferred because we have this skeleton equation (balanced for charge):
$\ce{Al -> Al(OH_2)_6^{3+}}... |
> 2 moles of electrons yields 2 moles of hydrogen gas
Doesn't your second equation say that 2 moles of electrons yields 1 mole of $\ce{H2}$? Following your reasoning, wouldn't 2 moles of $\ce{Al}$ yield 12 moles of electrons, which in turn would yield 6 moles of $\ce{H2}$? In any case, the balanced equation is $$\... |
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