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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Can assumptions made during calculation of ka of buffer solutions be justified?

We make many assumptions in sciences which are not always true but as they make little difference we ignore them for simplicity. But today I have decided that I can no longer be lured into using ...
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0answers
11 views

How do you calculate the proportion of ammonia produced from different pressures in the Haber process using the equilibrium equation?

I tried to write a increase in pressure to twice as much like this: $$\frac{2(x+1)^2}{(0.5-0.5x)2(1.5-1.5x)^3}=K$$
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1answer
31 views

Finding the equilibrium constant Kₚ, when temperature is given

At $1000~\mathrm{K}$, $K_p = 1.85$ for the reaction. $$\ce{SO_2 + \frac{1}{2}O_2 <=> SO_3}$$ What is the value of $K_p$ for the reaction $$\ce{SO_3 <=> SO_2 + ...
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1answer
22 views

Why is the water column empty in ICE table

In the ICE table pure solids and liquids have a value of one in the equilibrium expression but when we create an ICE table, why is the $\ce{H_{2}O}$ column empty? Should it not have a value of one?
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36 views

Chemical equilibrium coefficients [duplicate]

$$\ce{A + B -> C + D}\\ Keq= \frac{[C][D]}{[A][B]}\\ $$ Now if I write $$\ce{2A + 2B -> 2C + 2D}\\ Keq= \frac{[C]^2 [D]^2}{[A]^2 [B]^2} = Keq^2 $$ How is this possible?
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2answers
98 views

Determining if reaction is endothermic or exothermic using equilbrium constant

For the following reaction: $$W_{(s)}+4\,Br_{(g)}\rightleftharpoons WBr_{4(g)}$$ At 900 K, $K_{p}=100$ and at 2800 K, $K_{p}=5$. At higher temperatures, the equilibrium has shifted towards the ...
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32 views

Why is the equilibrium constant dependent only on the temperature? [duplicate]

Is it because of the Clausius Clapeyron equation or the Arrhenius equation or Van't Hoff equation or Le Chatelier's Principle just some theoretical explanation? Also it involves $\Delta H,\Delta G$, ...
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1answer
25 views

Applying the Le chateliers principle

I am an issue understanding the changes that take place when we decrease the pressure of a reaction. I have understood that when we increase the pressure the side having more number of moles wants ...
2
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1answer
34 views

Where can I find Equilibrium Constants?

When trying to develop mathematical models to show the concentration in a reaction, where can one find a database or good source of known equilibrium constants if it is not necessarily very convenient ...
2
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1answer
65 views

Why is the equilibrium constant given in litre per mole?

At $800\:\mathrm{K}$ a reaction mixture contained $0.5\:\mathrm{mol}$ of $\ce{SO2}$, $0.12\:\mathrm{mol}$ of $\ce{O2}$ and $5\:\mathrm{mol}$ of $\ce{SO3}$ at equilibrium. $K_c$ for the equilibrium ...
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44 views

Name the equation $\Delta G=\Delta G^{\circ}+RT \ln Q$

As the title states, what is the name of the equation $$\Delta G=\Delta G^{\circ}+RT \ln Q$$ My textbook does not explicitly state the name and I could not find anything on google.
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1answer
35 views

Determining vapor pressure from equilibrium constant

The reaction is $$CoCl_{2(s)}+6\,H_{2}O_{(g)}\rightleftarrows [Co(H_{2}O)_{6}]Cl_{2(s)}$$ Note that the reaction is at equilibrium. I have determined the value of $K_{p}=5.5\times10^{12}$. The next ...
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1answer
24 views

What does (heated) mean in a chemical equation?

I'm supposed to balance the following equation: $\text{Potassium chlorate (heated) --> Potassium chloride + Oxygen}$ But I don't understand what the (heated) means in front of the first element. ...
2
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0answers
24 views

Analytically combining Dynamic Equilibria that have a two way affect?

Lets say I want to model a water system as the following set of equilibria: $\ce{H2O <=> OH- + H3O+}$ | $\ce{A=[OH^{-}][H3O+]}$ $\ce{CO2 + H2O <=> H2CO3}$ | ...
5
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1answer
109 views

Acid-base equilibrium of NH4CN

I'm having difficulties understanding this problem. We have in the problem that $K_a$ for $\ce{HCN} = 6.2\cdot10^{-10}$ and $K_b$ for $\ce{NH3} = 1.8\cdot10^{-5}$. Write chemical equations to ...
3
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3answers
98 views

Why is the equilbrium constant expressed the way it is?

Why are the two molarity's multiplied and not added and why is each raised to the power of the coefficient rather than multiplied by it? What is the reasoning behind this form? Was it simply ...
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2answers
22 views

Finding the value of stoichiometric coefficient x

$\ce{2A_{(s)} + xB_{(g)} <=> 3C_{(g)}}$ $K_p=19.3, K_c=0.45, T=523K$ I work $\Delta n$ to be 1, So would $x$ be 1 or 2? I'm not sure if the coefficient is part of $\Delta n$.
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1answer
38 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 ...
2
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2answers
29 views

Find the color of the solution

The acid-base indicator methyl red has a $K_{a}$ = $1 \times 10^{-5}$. Its acidic form is red while its alkaline form is yellow. If methyl red is added in a colorless solution with a $pH = 7$, the ...
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1answer
37 views

Equilibrium Graphs

What if I2 and H2 began at the same concentration - then do we start at the same point? ... or is it acceptable to start at different concentrations...
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1answer
24 views

Equilibrium Practical Discussion Help

I understand the theory, but am struggling to answer the following discussion questions: (i) Why isn't this represented by: Fe3+ (aq) + 3 SCN- (aq) <-> Fe(SCN)3 (aq) Why do we dilute the ...
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2answers
197 views

Calculating pH of diprotic and amphoteric solutions

I am trying to understand this problem and its corresponding solution (complete solution not shown) First off, from the above one can see that the equilibrium constants when $\ce{H2ASO4-}$ ...
2
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1answer
47 views

4 Compounds in Equilibrium with One Another - Determine Their Equilibrium Concentrations

I know that if I have two compounds in equilibrium and I know $\ce{\Delta G}$, then I can use $$\ce{\Delta G=-RTlnK}$$ to determine the concentrations of the two components at equilibrium. I have 4 ...
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1answer
45 views

Ethanol and water hygroscopic equilibrium concentration

I am working with a company to help improve their reaction process where they use SDA 2B Alcohol (Karl Fischer titration has it at 99.66% EtOH, 0.3375% toluene). Specifically, I am attempting to ...
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1answer
42 views

Is there a database which give reaction constant?

For instance, I have a chemical reaction like : $$\ce{Fe^{2+} + $0.5$O2 + H^{+} ->Fe^{3+} + $0.5$ H2O}$$ And I would like to use Action-Mass law, but I need to have equilibrium constant for this ...
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1answer
35 views

How to create a buffer solution from NaOH and $\ce{CH3COOH}$?

In my chemistry book, they say that an approach to making a buffer solution of pH$=5.09$ is by adding an appropriate amount of strong base($0.052$ mol $\ce{NaOH}$) to $0.300L$ of $0.025 M$ ...
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1answer
39 views

Formation Constants; Lewis Acidity

I still distinctly remember reading about how Lewis acidity/basicity was characterized using kinetics. The reason given was that because formation constants are so large, these reactions are not ...
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1answer
18 views

Does Le Chatelier's principle apply to the gas inside an air mattress?

While sleeping on an air mattress yesterday a thought occurred to me. I had to re-inflate the air mattress since it was getting rather low and after it had a good stiffness to it, I went to sleep. The ...
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1answer
14 views

How does temperature affect equilibrium, according to Le Chatelier's principle?? [closed]

I want to understand this concept in detail. I am getting confused with increase in temperature backward reaction takes place or forward?? And how?? Proper explanation is needed.
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1answer
82 views

Why are solids and liquids not included in the equilibrium constant? What about in a reaction rate calculation?

Take for instance the rection $$\ce{H2(g) + I2(s) -> 2HI(g)}$$ The equilibrium constant would not include the solid $\ce{I2}$, but why is this? I have read that its concentration is a constant, ...
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1answer
91 views

Units for dissociation constant and relationship to Gibbs Free Energy

How does one "convert" between an equilibrium constant calculated from the Gibbs free energy for a dissociation reaction and experimentally determined dissociation constants? $$ \Delta ...
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67 views

How can we justify setting the affinity $\sum_i \mu_i \nu_i$ equal to zero at chemical equilibrium?

Let $\sum_A \nu_A A \rightarrow \sum_B \nu_B B$ be a general reaction whose progress during time interval $dt$ is measured by $d\zeta$, so the amount of reactants consumed and products generated in ...
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2answers
48 views

Carbonate Equilibrium Question: Finding concentration using concentration ratio and number of moles of acid

Lake water contains dissolved sodium carbonate and sodium hydrogen carbonate. The following equilibrium exists: $\ce{HCO3- <=> H+ + CO3^{2-}}$ $\frac{\ce{[CO3^{2-}]}}{\ce{[HCO3-]}} = 0.958$ ...
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15 views

A Question on Chemical Equilibrium [duplicate]

There's a property of the equilibrium constant that when we calculate the equilibrium constant for a reversible reaction, say it is $k_{1}$, and now we write the same equation by all the ...
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1answer
62 views

How to calculate the pH of a buffered solution with Henderson Hasselbalch?

Lets say you have a buffered solution containing $0.50~\mathrm{M}$ acetic acid ($K_a = 1.8 \cdot 10^{-5}$) and $0.50~\mathrm{M}$ sodium acetate, and you want to calculate the $\mathrm{p}\ce{H}$ of ...
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3answers
178 views

If all chemical processes are equilibria at least to some extent, where does the activation energy come from?

If all chemical processes are equilibria at least to some extent, then where does the energy to overcome the activation energy come from? Is a process with a very high activation energy (i.e. the ...
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1answer
90 views

How much carbonation is in one liter of commercial fountain coke-cola

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 ...
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2answers
42 views

What is true about this equation, at equilibrium, and why?

${H}_2O(s)\leftrightharpoons{H}_2O(l)$ A) the mass of ice must equal to the mass of water B) the mass water and the mass of ice each remain constant
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3answers
63 views

Specific question about multiple choice question

I have searched for this answer on line but I cannot find an answer. I know this is a Le Chatelier's principle question. The question: $\ce{2NO(g) + H_2(g) <=> N_{2}O(g) + H_{2}O} + ...
2
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1answer
40 views

Should binding constants be unitless when deriving fractional occupancy equations from reactions?

It is known that binding (aka association) constants are in fact unitless, as has been discussed here already. However, I'm not a chemist and am confused about when one should or should not use units ...
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1answer
28 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 ...
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1answer
20 views

Clarification on vapor pressure

If I have a glass of water, and the vapor pressure is the point of equilibrium where the liquid molecules are becoming gases and the gas molecules are colliding and becoming liquid at the same rate, ...
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1answer
53 views

How to prove this formula of extent of reaction?

We've a solution of $\ce{HCOOH}$ and Water $\ce{H_2O}$, I want to prove that the extent of this reaction is equivalent to : $$\xi=\frac{K_a}{K_a+10^{-\mathrm{p}H}}$$ Could you help try to figure ...
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1answer
55 views

pH of a solution of acetic acid and ammonium acetate

After studying ionic equilibrium, I was just making some wild questions and I was unable to calculate the $\ce{pH}$ of this solution. Assume, 1 mole of each was added to $1L$ solution of water. My ...
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1answer
124 views

Why is the equilibrium constant wrong for this Gibbs free energy problem?

Solid $\ce{NaHCO3}$ is heated to 90°C. At equilibrium the total pressure of the gases produced is 0.545 atm. Calculate $\ce{ΔG°}$ at 90°C for the reaction $\ce{2 NaHCO3(s) ⇌ Na2CO3(s) + H2O(g) + ...
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2answers
56 views

How to tell the pH of HC2H3O2?

The Question I am trying to Solve: The pH of a 0.500 M solution of $\ce{KC2H3O2}$. My First Question: How would I go about calculating this? My Second Question: Is the $\ce{H3O}$ in the middle of ...
2
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1answer
30 views

How to tell how far equilibrium is?

I am trying to solve a question that asks to compare Q vs. K. K = 4.2, and Q = 1.0. Problem Details: 2.0 mol of Samples of A, B, and C $\ce{A + B \rightleftharpoons 2C}$ I know that the ...
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4answers
98 views

How to explain the concept of mol and reactions involving mol quantities

From time to time I do little pro bono lessons for second grade in math, physics and chemistry. Recently I came across this question. In a container is $2~\mathrm{mol}$ of $\ce{SO3}$ (sulphur ...
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1answer
58 views

Please teach me how to solve this change in concentration over time problem

I've been going crazy with this question for the past 4 hours. I can't find much help in google cause it's not a traditional "find the velocity of the reaction" question. It's fine if you don't give ...
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3answers
58 views

Why is the reaction between hydroxide and water reversible, when the reaction between oxygen ions and water is not?

Why is the reaction between hydroxide and water reversible, when the reaction between oxygen ions and water is not? And is there a reason why the products of reaction 2) are written separately, ...