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27 views

Why are the equilibrium exponents stoichiometric when the rate law's are not? [duplicate]

I'm learning about rate law and equilibrium, and the textbook really hammers in that the exponents for the rate law must be determined experimentally - you can't just use the coefficients from the ...
-1
votes
1answer
171 views

How to calculate the equivalent mass of Na2S2O3? [closed]

Let us consider the following reaction $$\ce{I2 + 2 Na2S2O3 -> 2 NaI + Na2S4O6}$$ Now, in order to calculate the equivalent mass of $\ce{Na2S2O3}$, first I need to calculate it's $n$-factor which ...
0
votes
1answer
188 views

How to calculate the equivalent weight of KMnO4?

Let us consider the following reaction $$\ce{2 KMnO4 + 16 HCl → 2 KCl + 2 MnCl2 + 8 H2O + 5 Cl2}$$ Now, in order to calculate the equivalent mass of $\ce{KMnO4}$, first I need to calculate it's $n$-...
2
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0answers
51 views

Stoichiometry based on addition of simultaneous equilibria

I read on another equilibrium question that if two equilibria occur at the same time, then it is not accurate with actual stoichiometry to add the two equations and multiply the equilibrium constants $...
0
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2answers
110 views

Derivation of Gibbs free energy formula

Okay, so I'm trying to derive an important formula which states that - ∆G(r) = ∆G° + RTln( RQ ) where ∆G(r) is the instantaneous rate of change of Gibbs energy with ...
-2
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1answer
93 views

How to calculate the equilibrium constant for nitrogen, hydrogen, and ammonia?

$\pu{2 mol}$ of $\ce{N2}$ is mixed with $\pu{6 mol}$ of $\ce{H2}$ in a closed vessel of $\pu{1 L}$ capacity. If $50\%$ of $\ce{N2}$ is converted into $\ce{NH3}$ at equilibrium, what is the value of $...
0
votes
2answers
125 views

Weight of sodium acetate required to get to certain pH

How many grams of $\ce{CH3COONa}$ we need to dissolve in $\pu{2.50 L}$ of water to get a solution with $\mathrm{pH} = 9.00$? Given $K_\mathrm{a}(\ce{CH3COOH}) = 1.75\cdot 10^{-5}$ Like solving a ...
2
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1answer
1k views

Mixing Ca(OH)2 with Ca(NO3)2

Mixing $\ce{Ca(OH)_2}$ with $\pu{0.1 M}$ concentration of $\ce{Ca(NO3)2}$. What will actually happen in the process? What I will see with my eyes? I know that $\ce{Ca^2+}$ cation with concentration ...
-1
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1answer
50 views

Can i calculate the solution of the problem in more simple way?

and i got a serious question. During my exercises at home, i found that im struggling a lot while solving simple problem`s like this one: I have an aquatic substance with 0.100 M of $\ce{Mg(NO3)2}$ ...
1
vote
1answer
120 views

Grams of bicarbonate vs realeased CO2?

So, it's been a good two years since I've done chemistry and I have my first university lab in a few days and I'm sort of freaking out because I can't even remember how to do stoichiometry properly. ...
0
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2answers
580 views

Why is the rate of a reaction proportional to the concentrations of reactants raised to their stoichiometric coefficients?

Consider a gaseous state elementary reaction $$\ce{aA(g) + bB(g)} \overset{k_\mathrm{f}}{\underset{k_{\mathrm{b}}}{\ce{<=>}}}\ce{ cC(g) + dD(g)}$$ I know that for this reaction, $$\Delta G = \...
0
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1answer
127 views

Why doesn't hydroxide concentration equal concentration of carbonic acid and bicarbonate in a sodium bicarbonate solution?

To find the pOH of solution of $\pu{0.42 M}$ of $\ce{NaHCO3}$, given a $\ce{Kb}$ of $\pu{2.4E-8}$, my solution manual does the following steps: Reaction is similar to : $\ce{HCO3- + H2O <=> ...
2
votes
3answers
338 views

What is the best approach to balance this equation? Why I cannot do it efficiently?

What is the best approach to balance this equation? $$\ce{CO2 + H2O <--> C2H2 + O2}$$ I did it at first this way and I was not successful: \begin{align} \ce{4CO2 + H2O &<--> C2H2 + ...
2
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0answers
830 views

Why are the stoichiometric coefficients used as exponents in the chemical equilibrium constant?

From what I can ascertain, the formulation of the chemical equilibrium constant is somewhat arbitrary. I don't understand the motivation for putting the stoichiometric coefficients in the exponents. ...
-1
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1answer
333 views

How do I calculate the number of molecules in an equilibrium depending on a change in the equilibrium constant? [closed]

Consider 1000 molecules of $\ce{A}$ and 1000 molecules of $\ce{B}$ in a eucaryotic cell. The concentration of both will be about $\pu{10^-9 M}$. If the equilibrium constant $K$ for $\ce{A + B <--&...
3
votes
1answer
117 views

Given an unbalanced chemical equation, is it possible to determine the largest possible coefficient that could be used in the balanced equation?

I am writing a program to balance chemical equations, and would love to know if there is an algebraic way to determine the greatest possible coefficient that I would need to check.
4
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1answer
227 views

Why does multipying a scalar in both sides of a balanced chemical equation, change related quantities?

Stoichiometric coefficients appearing in a balanced chemical equation are unrelated to the actual concentration of reactant/products at any stage of a chemical reaction. They give information only ...
0
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1answer
45 views

Concentration and volumes

In the reaction: $$\ce{H2SO4 +CaCO3 \to CO2 + H2O + CaSO4}$$ Does altering the concentration of the sulfuric acid change the volume of the carbon dioxide produced [the volume of the sulfuric acid is ...
3
votes
1answer
143 views

Alternate solution for finding concentration in equilibrium

This question is still waiting for a better alternate answer. If you can add it then your answer can be chosen as accepted I came across a question yesterday A container contains three gases. A, B ...
2
votes
1answer
414 views

Equilibrium and Completeness of Reaction [duplicate]

In class we are currently learning about equilibrium and Le Chateliers principal. The principal makes sense but seems contrary to some other concepts. For example, using stoichiometry to calculate the ...
1
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2answers
502 views

Can acid concentration be determined from Ka values in a titration? [duplicate]

Say I have a sample of vinegar and I want to find the concentration of ethanoic acid in it. So I perform a titration using a $\mathrm{pH}$ meter, and using that data I can draw a $\mathrm{pH}$ curve ...
6
votes
1answer
2k views

Proof that Equilibrium Constant is a Ratio of Rate Constants

I have a question about this proof that shows the relationship between the rate constant and the equilibrium constant. In this proof, the assumption is that the reaction is $(a+b)$th order in the ...
3
votes
1answer
20k views

Relationship between rate equation and equilibrium constant

I have read mannaia's answer on the question of 'rate order and confusion', as well as Nicolau Saker Neto's answer to a related question. They have both been very helpful. As I understand, the ...
0
votes
1answer
345 views

A sample of tap water is found to be 0.025 M in Ca2+. If 105 mg of Na2SO4 is added to 100.0 mL of the tap water, will any CaSO4 precipitate?

Given: Ksp of CaSO4 is 7.10*10^-5 Molar mass of Na2SO4 is 142.04g/mol My Attempt: Step 1 - figure out molar solubility of CaSO4 √7.10*10^-5 = 8.43*10^-3M Step 2 - convert Na2SO4 from mass to ...