The state in which both reactants and products are present at concentrations which have no further tendency to change with time.

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How to do equilibrium constant [on hold]

Consider the reaction: CO(g)+H2O(g)⇌CO2(g)+H2(g) An equilibrium mixture of this reaction at a certain temperature was found to have [CO]= 0.0243M , [H2O]= 0.0145M , [CO2]= 0.200M , and [H2]= 0.0294M ...
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18 views

What is the equilibrium constant? [on hold]

Consider the reaction: 2H2S(g)⇌2H2(g)+S2(g) An equilibrium mixture of this reaction at a certain temperature was found to have [H2S]= 0.502M , [H2]= 3.24×10−2M , and [S2]= 7.84×10−3M .What is the ...
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44 views

Aqueous vs. Solid

I've been having a conceptual struggle with these two states for a while now, and I'd like to get it cleared up. A compound AB dissolves in water. $$\ce{AB(s) + H2O <-> A+(aq) + B- (aq) + ...
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1answer
21 views

What kind of equilibrium constant we use for Gibbs free energy and Van't Hoff equation?

We know that Gibbs free energy is same as negative of 8.314 times temperature in Kelvin times natural logarithm of equilibrium constant, or: Then, we also know Van't Hoff equation, like: (R in ...
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32 views

Calculation of Equilibrium Constant

How do You solve this? $$\ce{2SO2 + O2 -> 2SO3}$$ Starting with $1$ mol of $\ce{SO2}$ and $1$ mol of $\ce{O2}$ in a 1 litre flask, the equilibrium mixture required $0.4$ mol $\ce{MnO4^-}$ in ...
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3answers
43 views

How does equilibrium change when the products are solid and gas?

$$\ce{CaCO3(s) <=> CaO(s) + CO2(g)}$$ How will the amount of each element change if the pressure is increased? My guess is that the equilibrium will shift to the left, because the right side ...
4
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1answer
85 views

Conceptualizing Multiple Equilibria

Take the reaction: $$ (1) \; \ce{A + B <=>X + Y}, \; K_1=\frac{[X][Y]}{[A][B]} $$ Now assume that X isomerizes to Z according to: $$ (2) \; \ce{X <=> Z}, \; K_2=\frac{[Z]}{[X]} $$ We can ...
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1answer
21 views

If absorbance is 0, what is the equilibrium constant?

If the absorbance of something is 0, what is the equilibrium constant? In a reaction, the absorbance is 0, so the concentration of the product is 0. The concentration of one of the reactants is also ...
1
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1answer
45 views

Why isn't ΔG equal to zero for this equilibrium reaction?

In the reaction $\ce{E(g) <=> P(g)}$ at 25°C, equilibrium is reached when the pressure of the product is 0.100 that of the reactant. What is $\Delta G$ in joules? Using $\Delta G = \text{RT} ln ...
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1answer
46 views

How many milliliters of 0.202M NaOH to 25.ml of 0.0233M salicylic acid to adjust the pH to 3.5

I'm studying for exam tomorrow and ran into another question that i'm having trouble with. This one seems easy but I am not getting the right answer. How many milliliters of $0.202$ M NaOH should ...
0
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2answers
66 views

When we dilute a weak acid, pH increases but dissociation increases

When water is added to a weak acid like ethanoic aicd, number of ethanoic acid molecules that dissociate increases however, pH increases (less acidic)... but why?
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79 views

Why does free chlorine in the stratosphere lose its ozone-depleting potential after about 100,000 reactions?

Free chlorine ($\ce{Cl}$) in the stratosphere can deplete ozone ($\ce{O3}$) as follows: $$\ce{Cl + O3 -> ClO + O2}$$ The chlorine atoms can then react with oxygen and return to the beginning of ...
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1answer
23 views

Changes in which factors affect both the rate and the rate constant of a first order reaction?

Changes in which factors affect both the rate and the rate constant of a first order reaction? I. temperature II. concentration (A) I only (B) II only (C) Both I and II (D) ...
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1answer
37 views

Question on calculating solubility from Ksp

For example, given a reaction $\ce{NaCl -> Na+ + Cl-}$ and its $Ksp$ value, I know that you can set up $$Ksp\; =\; \left[ \ce{Na^{+}} \right]\left[ \ce{Cl^{-}} \right]$$ and solve from there. My ...
6
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2answers
188 views

Pressure and LeChatelier's Principle

We know that if a system's equilibrium is exposed to a stress, the system shifts to relieve that stress. According to my teacher, certain kinds of pressures are stresses and others are not. Normally, ...
2
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1answer
50 views

Why does the equilibrium constant depend on the temperature but not on pressure and concentration?

According to my textbook (and intuitively) certain changes when the aforementioned 3 variables are altered occur in accordance with Le Chatelier's Principle. However, what I don't understand is what ...
3
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1answer
95 views

Determine the equilibrium constant for this reaction

I tried to do the question below and I want to make sure if I did correctly. The question is: Ions B and C react to form complex BC. If 15.0 mL of 1.00 M B is combined with 15.0 mL of 1.00 M C, and ...
3
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1answer
37 views

problem with partial pressures

This is a question I solved in class: At 35 degrees, $\ce{N_2O_4}$ is 15% dissociated in a flask at a pressure of 1.2 atm. Calculate $K_p$ Equation: $$\ce{N_2O_4(g)<=>2NO_2 (g)}$$ ...
3
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2answers
93 views

Equillibrium Constant

I read in my textbook that if we multiply a chemical reaction by some factor(let's say $b$) its new equilibrium constant becomes $K^b$.But I don't understand why this happens.. What is the difference ...
3
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1answer
26 views

Heterogeneous Equilibrium Without Gas

We know that for homogeneous mixtures the equilibrium constant is determined using both concentration of reactants and of products. For heterogeneous equilibrium involving a gas and a liquid or a ...
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145 views

How many grams of each substance will be present at equilibrium?

In the following reaction, $K_\text{c}=4.0$: $$\ce{C2H5OH + CH3COOH <=> CH3COOC2H5 + H2O}$$ A reaction is allowed to occur in a mixture of $17.2~\mathrm{g}~\ce{C2H5OH}$, ...
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46 views

Proton transfer equilibrium in bisulphite adducts

In the addition of $\ce{NaHSO3}$ to aldehydes and methyl ketones (higher ketones do not respond well to this reaction), crystalline addition products are formed. An $\ce{-SO3H}$ and an $\ce{-OH}$ ...
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1answer
46 views

$\ce{NO2-}+\ce{H2O}$

I'm reviewing for my AP Chem acid-base equilibrium test, and I'm working problems out of the book, I have a problem that asks: "Predict the products of the following acid-base reactions, and predict ...
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1answer
40 views

What are the concentrations of these chemicals when equilibrium is established in the reaction?

the question is, Lead metal is added to $0.100\ \text{M} \ \ce{Cr^{+3}(aq)}$. What are $[\ce{Pb^{+2}}]$, $[\ce{Cr^{+2}}]$, and $[\ce{Cr^{+3}}]$ when equilibrium is established in the reaction? $$K_c = ...
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1answer
33 views

Chemical equilibria and changes in concentration

I learned that if concentration of reactants or products is changed, the position of equilibrium changes but value of $K_c$ remains the same. This just does not make intuitive sense to me... I mean ...
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69 views

Can luciferin + ATP → luciferyl adenylate + PPi be reversed?

Reading about the light emitting reaction of luciferin + ATP, catalysed by luciferase I am confused about the following. On this webpage the partial formula is written as: luciferin + ATP → ...
3
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1answer
66 views

existence and stability of Bifluoride ion

Consider the following homework question:- Statement 1. The $\ce{HF2^-}$ ions exist in solid state and also in liquid state but not in aqueous state. Statement 2. The magnitude of ...
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1answer
59 views

Chemical Potential of Idea gas?

Let's say we have a mixture of different ideal gases. I found that the chemical potential of a single component of the mixture is $$\mu_{i}=g_{i}^{0}+Ln(\frac{f_{i}}{P_{ref}})$$ where $f_{i}$ is the ...
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1answer
71 views

How do I determine the equilibrium concentration given Kc and the concentrations of component gases?

I feel my method for solving it is correct and I've checked my calculations yet I can't get the right answer. Nitrogen and oxygen gases may react to form nitrogen monoxide. At 1500 °C, $K_c$ equals ...
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1answer
38 views

Figuring out the concentration of weak polyprotic acids in presence of strong acid

We have a $\rm{0.1 \ M}$ solution of $\rm{H_2S}$ with a $\rm{0.1 \ M}$ solution of $\rm{HCl}$. We need to figure out the concentration of $\rm{S^{2-}}$ ions at equilibrium. $$\rm{H_2S ...
2
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2answers
104 views

For a given teabag and dunking duration - will I get more caffeine in a bigger cup or the same amount?

When choosing a cup of tea, I can choose a big cup or a small cup. I'm wondering if I get more caffeine with the bigger cup or the same amount of caffeine. (in moles) My question is: For a given ...
3
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1answer
116 views

Determining standard Gibbs free energy for water?

I am dealing with the dissociation of water into its components hydrogen and oxygen and I am trying to determine the standard Gibbs free energies of each component. My professor said if the substance ...
5
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168 views

Why do solutions become saturated?

Why can a solvent dissolve only a particular amount of solute? If we add more solute to the solution, the number of solute particles in contact with water increases. So rate of dissolution should ...
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1answer
73 views

Negative molarity problem

There is a reaction: $\ce {ClF3 <=> ClF + F2} $ Then the equilibrium constant is: $\ce {Kc = 2,48 x 10^{-3}}$ At first, I have $\ce {[ClF3] = 0,25 M} $, $\ce {[ClF] = 0,031 M} $, and $\ce ...
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1answer
40 views

Why does the position of equilibrium depend only on the relative Gibbs energies of the products and the reactants?

The position of equilibrium, I read, is dependent only on the relative Gibbs energies of the products and the reactants. Why is this so? Surely one must take into account the entropy of mixing of the ...
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1answer
76 views

Calculating approximate pH of polyprotic acids

When I took up ionic equilibria and titrations after a long break, I found it hard to solve the questions regarding pH calculations of polyprotic acds. Consider these two questions as examples:- ...
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45 views

Equilibrium rate constants forward and backwards

Correct me If I am wrong, given a reaction at equilibrium, if we say add more concentration of products to the reaction, the rate going backwards would increase to try to get back to equilibrium. I ...
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1answer
78 views

Unfavorable reactions

How can you make an unfavorable reaction go backwards? From my understanding if we wanted a reaction at equilibrium to go backwards (i.e. form reactants from products), we would add more product into ...
0
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1answer
65 views

Ionic Product of Water

Why is the ionic product for water ($K_w$) temperature dependent? The concentration of $\ce{H+}$ and $\ce{OH-}$ ions in pure water is $\ce{[H+] = [OH^{-}]} = 1.0\times 10^{-7} M$ at $25^{o}C$, and ...
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1answer
42 views

Thermodynamics and equilibrium constant

I just wanted to make sure how we can know whether it is $K_c$ (equilibrium constant of concentrations) or $K_p$ (equilibrium constant of pressures) which "comes out" of the equation, $\Delta G^o= -RT ...
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1answer
41 views

Thermodynamics effect of change of temperature on equilibrium

I'm studying thermodynamics and I don't understand, why, when we are asked which effect has a rise in temperature on the equilibrium constant of a reaction, we can't use the formula: $\Delta G= \Delta ...
0
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1answer
54 views

Which of these thermodynamic relationships is true for a system at equilibrium?

Which of the following is true at equilibrium $$T \Delta{S} = \Delta{H}$$ $$T \Delta{s} = \Delta {G}$$ I think it's the first one but I just wanted to be sure.
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63 views

Relationship in equilibrium constants

$\ce{2CH4(g) + O2(g) \rightleftharpoons 2CO(g) + 4H2(g)}$ Equal numbers of moles of $\ce{CH4}$ and $\ce{O2}$ are drawn into a sealed container and the system is left until it reaches ...
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2answers
32 views

How to increase equilibrium of Cl2

$\ce{Heat\ +\ PCl5(g)\ \rightleftharpoons\ PCl3(g)\ +\ Cl2(g)}$ According to the process above, which of the following can be done to increase the number of moles of $\ce{Cl2}$ in a sealed container ...
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82 views

Does the number of H+ ions in solution go up on dilution of a weak acid?

In my textbook, a footnote says: In case of weak acids, on dilution the total number of $H^{+}$ ions in solution increases because dissociation of the weak acid increases This didn't make sense ...
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1answer
46 views

Similarity between Ecell and equilibrium constant Kc

$$\ce{Cu^{2+} + Zn<=>Zn^{2+} + Cu}$$ $K_c=1.9*10^{37}$ $E_{cell}=1.1V$ I know that they both suggest that the forward reaction is going to completion but can someone please tell me a bit ...
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1answer
60 views

Equilibrium constant calculation from concentrations

Consider the following equilibrium: $\ce{A2\ _{(g)} + 2B_{(g)} <=> 2AB_{(g)}}$ A chemist puts 8.0 moles of $\ce{A2}$ and 10.0 moles of $\ce{B}$ into an evacuated 1.0 L container. The system ...
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1answer
48 views

how to increase Keq(equilibrium) with temperatrue

$$\ce{C_{(s)} + H_2O_{(g)} {<=>} CO_{(g)} + H_{2(g)}}$$ $$\Delta {H} = +131KJ$$ If the reaction is in a state of equilibrium under standard conditions, what can be done to increase the ...
3
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2answers
73 views

Does using stonger soaps help me lose weight?

Soaps are amphiphilic molecules that, practically, removes body oils from the surface of the skin. The body, on the other hand, always replenishes sebum through the sebaceous glands after a certain ...
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1answer
43 views

Belousov-Zhabotinsky reaction

The Belousov-Zhabotinsky reaction is a very fascinating one. The Chemistry behind the reaction concerns thermodynamics and equilibrium. I want to perform the experiment, but I'm not able to find ...