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I'm an IB Chemistry student and I had to do a back titration lab where 1g of a powdered antacid tablet were mixed with 50mL 1M HCl, and the mixture was titrated using 0.2 M NaOH; the NaOH was to neutralize the leftover HCl that hadn't reacted with the antacid. The active ingredient in the antacid is CaCO3.
It took m... |
In chemical analysis usually do three times the same experimet, so you can minimize experimental errors.
After that, in order to find where is the error you can check:
Has everyone in you class use the same HCl and NaOH solutions (taken from the same bottle i.e.?
The antiacid tablets are all the same (given by... |
In chemical analysis usually do three times the same experimet, so you can minimize experimental errors.
After that, in order to find where is the error you can check:
Has everyone in you class use the same HCl and NaOH solutions (taken from the same bottle i.e.?
The antiacid tablets are all the same (given by... |
In terms of producing gold nano flakes, Guo et al. have mentioned in their journal called 'Facile synthesis of micrometer-sized gold nanoplates through an aniline-assisted route in ethylene glycol solution', they added aniline to the solution of chloroauric acid in ethylene glycol at 95 degree Celsius. However, I could... |
In terms of producing gold nano flakes, Guo et al. have mentioned in their [journal][1], they added aniline to the solution of chloroauric acid in ethylene glycol at 95 degree Celsius. However, I couldn't figure out the step by step chemical reaction in it. Can anyone please explain me the reaction procedure or guide m... |
i'm trying to make a rocket, so i searched on internet about rocket fuel and i saw the rocket candy ( KNO3 + Sugar ) but i was thinking about other methods.
Do you know the experience with HCL + AL that you can do a bomb by using pressure on the bottle. I did this experience lot of times, but had once the bottle d... |
Which is the best rocket fuel? |
> Why are ionic reactions extremely fast, as compared to other gaseous
> reactions?
The ionic reactions (precipitations, neutralizations etc.) are extremely fast (somewhere about $10^{12}$ times faster) than gas-phase reactions and other ordinary reactions in solutions (inversion, substitution etc). Why is this... |
Speed of ionic reactions? |
My book says, methyl chloride, methyl bromide, ethyl chloride and some cholorofluromethanes are gases at room temperature, whereas higher members are liquids or solids. Why?
With this question, I got another question for which the former would be subset. How to determine whether a compound is gas or liquid or solid ... |
I searched on internet about rocket fuel and the most common fuel is KNO3 + Sugar ( Rocket Candy ) , but i think that i could use another fuel methods, like using can with gas or using HCL + AL.
My question is which one ( KNO3 + Sugar , can with gas or HCL + AL ) is the best? Can i increase the performance by inc... |
I searched on internet about rocket fuel and the most common fuel is KNO3 + Sugar ( Rocket Candy ) , but i think that i could use another fuel methods, like using can with gas or using HCL + AL.
My question is which one ( KNO3 + Sugar , can with gas or HCL + AL ) get more performance? Can i increase the performan... |
I searched on internet about rocket fuel and the most common fuel is KNO3 + Sugar ( Rocket Candy ) , but i think that i could use another fuel methods, like using can with gas or using HCL + AL.
My question is: Which one ( KNO3 + Sugar , can with gas or HCL + AL ) gets more performance? Can i increase the perform... |
- My book says, methyl chloride, methyl bromide, ethyl chloride and some cholorofluromethanes are gases at room temperature, whereas higher members are liquids or solids. Why?
- With this question, I got another question for which the former would be subset. How to determine whether a compound is gas or liquid or ... |
Question related to uncertainty propagation.
I was taught that when adding/subtracting measurements, add the absolute uncertainties, and when multiplying/dividing measurements, add the relative uncertainties.
I have a problem in a lab where I need to find the difference between two measurements that are very close to... |
Uncertainty propagation question? |
Since fluorine has its valence electrons in the n=2 energy level, and since chlorine has its valence electrons in the n=3 energy level, one would initially expect that an electron rushing towards fluorine would release more energy, as it would land in the n=2 energy level, whereas in chlorine, the electron would land o... |
Why does chlorine have a higher electron affinity than fluorine? |
Please describe why copper only reacts with oxygen and not nitrogen in the air. Isn't nitrogen a negative ion, and copper positive, so wouldn't that mean that copper and nitrogen would want to form bonds? |
Why does copper not react with nitrogen? |
Fluorine, though higher than chlorine in the periodic table, has a very small atomic size. This makes the fluoride anion so formed unstable due to a very high charge/mass ratio. Also, fluorine has no d electrons which limits its atomic size. As a result, fluorine has an electron affinity less than that of chlorine.
... |
in quantum mechanics, while writing the wave function we can do product of spatial and spin parts, what it means? and what is the meaning of spatial wave function and spin wave function? |
how can we write the wave function in quantum mechanics? |
In quantum mechanics, while writing the wave functions we can take a product of the spatial and the spin parts.But what does it means? What is the meaning of the spatial wave function and the spin wave function? |
How can we write the wave function in quantum mechanics? |
I frequently encounter two ways of writing enthalpies of some process, e.g. for the enthalpy of formation:
1. $\Delta_{r} G$ (or $\Delta_{R} G$)
2. $\Delta G_{r}$ (or $\Delta G_{R}$)
On the IUPAC Gold Book webpage they used the first notation (although the use of upper- and lower-case descriptors varies, see [... |
What's the convention for the symbols of enthalpies of formation, reaction, etc.? |
Noob question here. I am a mathematics student doing a course in thermodynamics and am working on the basics now. The question I am asked is: Suppose two states differ in energy by one $eV$. What can be said about the ratio of the population at $T=300K$. Now it is clear that I will use the formula:
$$\frac{N_i}{N_j} =... |
What units do I use for energy in the Boltzman distribution? |
What units do I use for energy in the Boltzmann distribution? |
For solids where the compound contains defects, the stoichiometric equation deviates from the "pure" one. How are these compounds determined? I am looking in my chemistry book but I do not see anything on it. Are there some resources on this? |
How are non-Stoichiometric compounds determined? |
Calculate the molality, molarity and mole fraction of a CuSO4
in a 17% m/m aqueous solution (density of the solution is 1.367 g/mole)
I did .17 * 1.367 to find grams of CuSO4
and .83 * 1.367 to find grams of H2O
Then used to them calculate:
molarity = 0.00146 M
molality = 1.287 m
Mole fraction = 0.02... |
How to calculate molality, molarity and mole fraction given density (g/mole)? |
If you facilitate a weak acid base reaction. I.e. NaOH + H2SO4. All of it may not react and the solutions will not neutralize. How can you determine how much actually reacted? |
Calculate the molality, molarity and mole fraction of a $\ce{CuSO4}$
in a 17% m/m aqueous solution (density of the solution is 1.367 g/mole)
I did .17 * 1.367 to find grams of $\ce{CuSO4}$
and .83 * 1.367 to find grams of $\ce{H2O}$
Then used to them calculate:
molarity = 0.00146 M
molality = 1.287 m
... |
If you facilitate a weak acid base reaction. i.e. $\ce{NaOH + H2SO4}$. All of it may not react and the solutions will not neutralize. How can you determine how much actually reacted? |
I searched on internet about rocket fuel and the most common fuel is $\ce{KNO3}$ + Sugar ( Rocket Candy ) , but i think that i could use another fuel methods, like using can with gas or using $\ce{HCL + AL}$.
My question is: Which one ( $\ce{KNO3}$ + Sugar , can with gas or $\ce{HCL + AL}$ ) gets more performance... |
Is there an online database of acid and basic dissociation constants, all in one place, free to use? |
So recently I have undertaken some research with some organometallic chemistry involved, specifically regarding that of ruthenium-aryl compounds. Trying to understand the chemistry of the central metal ion, I noticed something weird a couple of weeks ago, from Wikipedia: Ruthenium only has one electron in that orbital,... |
Why does Ruthenium only have one electron in its 5s orbital in the neutral oxidation state? |
So recently I have undertaken some research with some organometallic chemistry involved, specifically regarding that of ruthenium-aryl compounds. Trying to understand the chemistry of the central metal ion, I noticed something weird a couple of weeks ago, from Wikipedia: Ruthenium only has one electron in that orbital,... |
For solids where the compound contains defects, the stoichiometric equation deviates from the "pure" one. How are these compounds determined? I am looking in my chemistry book but I do not see anything on it. Are there some resources on this?
UPDATE:
After doing some thinking, I considered the [Auger Electron ... |
So recently I have undertaken some research with some organometallic chemistry involved, specifically regarding that of ruthenium-aryl compounds. Trying to understand the chemistry of the central metal ion, I noticed something weird a couple of weeks ago, from Wikipedia: Ruthenium only has one electron in that orbital ... |
My teacher in college says that bonds between Metals and No Metals are Ionic.
Metal - Metal = Metalic
Non metal - Non metal = Covalent
I have to write about Cl Cu2, and found in Wikipedia that if you substract electronegativity you get what bond it is.
Cl = 3,16
Cu = 1,90
3,16 – 1,90 = 1,26.
X < 0.4 = ... |
As you may know, the reaction quotient $Q_c$ is defined by the equation
$$
Q_c = \frac{[C]^\gamma [D]^\delta}{[A]^\alpha [B]^\beta}
$$
for the chemical reaction
$$
\alpha A + \beta B \rightarrow \gamma C + \delta D.
$$
This is something I've been struggling to understand at an intuitive level. Why is $Q_c$ th... |
Why does the reaction quotient use the products (multiplications) of reactants and products, rather than their respective sums? |
My teacher in college says that bonds between metals and nonmetals are Ionic.
$ \ce{Metal - Metal} $ => Metalic bond
$\ce{Non metal - Non metal}$ => Covalent bond
I have to write about $\ce{Cl Cu2}$, and found in Wikipedia that if you subtract electronegativity you get what bond it is.
Cl = 3,16
Cu = 1,9... |
From [Oxtoby et al, Principles of Modern Chemistry, 7th edi p219][1] and Levine, Quantum Chemistry, 5th edi, p314, the orbital energies of Sc and the elements beyond, 3d<4s. The electrostatic repulsion makes energy of 3d$^3$ higher than 3d$^1$4s$^2$.
Just my pure guess, Ru is bigger than Fe, electrostatic repulsi... |
To explain the characteristic X-ray emission peaks for various elemental targets, a formula was developed which was similar in construct to the rydberg equation for H-atom as derived by the Bohr-model.
$$\bar \nu=R(\frac{1}{n_f^2}-\frac{1}{n_1^2})(Z-\sigma)^2$$
where $\bar \nu$ is the wave number, $\sigma=1$ fo... |
Understanding moseley's law from the rydberg-type equation? |
My teacher in college says that bonds between metals and nonmetals are Ionic.
$ \ce{Metal - Metal} $ $\Rightarrow$ Metalic bond
$\ce{Non metal - Non metal}$ $\Rightarrow$ Covalent bond
I have to write about $\ce{Cl Cu2}$, and found in Wikipedia that if you subtract electronegativity you get what bond it is.
... |
I have a solution with **only** CO<sub>3</sub><sup>2-</sup> ions and water.
What would happen with the carbonate ions if I were to evaporate the water of that solution (in vacuum)?
|
Evaporating the water of a solution of only CO32- ions and water gives? |
Currently i am doing some research on optical properties of a oxide material and for that purpose i have done some photoluminescence study on it. Because this is an ongoing research i cant divulge much information here. I have used "$Ex$" excitation wavelength for getting emission spectra for my oxide sample. I have p... |
My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: ... |
Why is Finkelstein reaction restricted for specific conditions? |
For this case, let's say there are two identical chambers connected by a small tube, constant pressure and temperature. There's a closed valve that separates the two chambers. Within the chambers there are two ideal gases (doesn't matter which, I think; they're ideal gases). I release the valve and the contents of the ... |
> My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: Reflux... |
> Halogens ($Cl_2$ and $Br_2$ ) react with alkanes in the presence of ultraviolet light to form haloalkanes.This reeaction is free radical substitution and gives a mixture of mono, di or polysubstituted haloalkanes which are difficult to separate into pure components. Moreover, the yeild of any one compound is low be... |
> The branched chain compounds have lower boiling points than the corresponding straight chain isomers. For example,
$$CH_3CH_2CH_2CH_2CH_3$$$$No~branching-Pentane~(n-pentane)~(b.p.=309K)$$
$$CH_3CH(CH_3)CH_2CH_3$$ $$One~branching-2-Methylbutane~(Iso-pentane)~(b.p.=301K)$$... |
Why do branched chain compounds have lower boiling points than the corresponding straight chain isomers? |
Crystal Field Theory explains colors of Coordination compounds as follows : A d-orbital splits into multiple orbitals, the process being called crystal field splitting. When white light falls on the compound, an electron makes a transition into a higher state thus absorbing a particular wavelength of light. The rest of... |
> My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: Reflux... |
> My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: Reflux... |
Can we prepare alkyl chloride or alkyl bromide by Finkelstein reaction? |
> My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: Reflux... |
Why are NaCl and NaBr not soluble, whereas NaI is soluble in acetone (in the Finkelstein reaction)? |
> My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: Reflux... |
Can we prepare alkyl Fluoride by Finkelstein reaction? |
> My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: Reflux... |
> My book says:
Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide in dry acetone.
$\ce{R-X~+~NaI->[\ce{acetone,~reflux}]R-I~+NaX}$
$(X=Cl,~Br;R=alkyl ~group)$
*NOTE*: Reflux... |
What does the Sm5Ge4 orthorhombic structure look like? |
Why does a wood fire create benzine? |
Why does a wood fire create benzene? |
A solution made of two or more compounds have adhesive and cohesive forces. Cohesive forces are the attractive forces between the same molecules. Adhesive forces are the attractive forces between different molecules of the solution.
A real solution shows positive deviation from Raoult's law when the cohesive forces ... |
For example can I introduce salts that have a chaotropic or kosmotropic affect on ethanol? Or is this phenomenon restricted to water? If this phenomenon does occur in other polar solvents, does it follow the Hofmeister series as well? Are there any papers out there on this phenomenon in polar non-aqueous solvents? |
Do chaotropic and kosmotropic affects occur in polar non-aqueous media? |
When you drop a bottle of soda, the dissolved CO2 starts nucleating. Opening it before it's 'settled' will trigger more nucleation and usually makes a mess.
Why does the shock trigger nucleation?
Secondarily, is it the same mechanism in play when you shake a bottle? And what about teh physical state changes as it... |
How does shock trigger nucleation of gasses dissolved in a liquid? |
When you drop a bottle of soda, the dissolved CO2 starts nucleating. Opening it before it's 'settled' will trigger more nucleation and usually makes a mess.
Why does the shock trigger nucleation?
Secondarily, is it the same mechanism in play when you shake a bottle? And what about teh physical state changes as it... |
Every one have observed that when we pour cool water into a transparent glass (or simply glass), some droplets accumulate on the outside part. Did the droplets come pass through the glass? If they didn't, why is there accumulation of water droplets outside the glass?
![enter image description here][1]
[1]: ht... |
Is quite reductive think that pH is the onlyfactor that determinate the health of your teeth, the content of carbohydrate have a strong effect too.
However in fact to my knowledge clear vodaka have one of the highest pH and very few carbohydrates so indeed is one of the most "teeth friendly alcohol drink".
These is t... |
#Foreword
This topic is treated in most books and sites so I've try to explain it to you in a more unusual and friendly way to gasp the concept but maybe the canonicals explanations are more suited for exams and serious conversation.
#First step idealize and simplify the Raoult law
You can see Raoult law as the mo... |
#Foreword
This topic is treated in most books and sites so I've try to explain it to you in a more unusual and friendly way to gasp the concept but maybe the canonicals explanations are more suited for exams and serious conversation.
#First step idealize and simplify the Raoult law
You can see Raoult law as the mo... |
When you drop a bottle of soda, the dissolved $CO_2$ starts nucleating. Opening it before it's 'settled' will trigger more nucleation and usually makes a mess.
Why does the shock trigger nucleation?
Secondarily, is it the same mechanism in play when you shake a bottle? And what about teh physical state changes as... |
When you drop a bottle of soda, the dissolved $\ce{CO_2}$ starts nucleating. Opening it before it's 'settled' will trigger more nucleation and usually makes a mess.
Why does the shock trigger nucleation?
Secondarily, is it the same mechanism in play when you shake a bottle? And what about teh physical state chang... |
A solution made of two or more compounds have adhesive and cohesive forces. Cohesive forces are the attractive forces between the same molecules. Adhesive forces are the attractive forces between different molecules of the solution.
A real solution shows positive deviation from Raoult's law when the cohesive forces ... |
Find the mass of $NaBrO_3$ required to prepare $150 ml$ of $0.75N$ solution based on the reaction $$\ce{BrO_3^- +6H^+ +6e^- \bond{->}Br^- +3H_2O}$$
My analysis:
$150 ml$ solution of $0.75N$ means $0.1125$ equivalents of $NaBrO_3$ are present in the solution. Since, according to the given equation, n-factor (of equi... |
To understand the commonly quoted magnetic value of coordination complexes (central ion) we use
$$m_l=\sqrt{n(n+2)} \text{BM where BM}=\frac{e\hbar}{2m_e}\text{JT}^{-1}$$
$n$=number of unpaired electrons.
> How did we derive this equation?
I know the orbital angular momentum of electron is given by $\sqrt... |
Magnetic moment of coordination complexes? |
Find the mass of $\ce{NaBrO_3}$ required to prepare $150 \text{ml}$ of $0.75N$ solution based on the reaction $$\ce{BrO_3^- +6H^+ +6e^- \bond{->}Br^- +3H_2O}$$
My analysis:
$150 \text{ml}$ solution of $0.75N$ means $0.1125$ equivalents of $\ce{NaBrO_3}$ are present in the solution. Since, according to the given equ... |
As you may know, the reaction quotient $Q_c$ is defined by the equation
$$
Q_c = \frac{[C]^\gamma [D]^\delta}{[A]^\alpha [B]^\beta}
$$
for the chemical reaction
$$
\alpha A + \beta B \rightarrow \gamma C + \delta D.
$$
This is something I've been struggling to understand at an intuitive level. Why is $Q_c$ th... |
Halogens bonded to benzene ring has three lone pairs. These three electron pairs can cause resonance in benzene ring. But, halogens are also highly electronegative and thus they have strong -I effect. So, they are deactivating groups. But, why are they ortho para directing?
|
To me your answer is correct. It seems that the book result have a '2' dividing the final result. Could you post all the text of the book exercise? Two possibilities, the result from the book is wrong (could be) or there is a mistake in one of the values (75 ml instead 150, 0.375 N instead 0.75 N...). |
I couldn't find this in any textbooks, so I guess I will ask this here. What is the physical state of $HX$ when reacting with alcohol (nucleophilic substitution) and alkenes (electrophilic addition) respectively?
----------
For electrophilic substitution of benzene with bromine, what is the state of br... |
What are the states of $HX$ when reacting with alcohol and alkenes respectively, and $Br_2$ when reacting with benzene? |
I couldn't find this in any textbooks, so I guess I will ask this here. What is the physical state of $\ce{HX}$ when reacting with alcohol (nucleophilic substitution) and alkenes (electrophilic addition) respectively?
----------
For electrophilic substitution of benzene with bromine, what is the state ... |
What are the states of HX when reacting with alcohol and alkenes respectively, and Br_2 when reacting with benzene? |
I'm referring to the Shuttle Battery recently announced (read more on it [here](http://www.connexxsys.com/en/en_shuttle.html)) that suggests that:
> The energy density of the device is up to 7,700 Wh/L. It is more than 5 times
higher than state-of-the-art (SOA) Li-ion (550Wh/L), and comparable to fossil
fuel (10... |
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