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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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 ...
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20 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 ...
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62 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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39 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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33 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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20 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. ...
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21 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: $\ce{H2O <=> OH- + H3O+}$ | $\ce{A=[OH^{-}][H3O+]}$ $\ce{CO2 + H2O <=> H2CO3}$ | ...
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94 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 ...
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96 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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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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36 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 ...
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27 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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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
20 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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172 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 $\ce{H2ASO4-}$ ...
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1answer
43 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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40 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
35 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
29 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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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
13 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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65 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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61 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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65 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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34 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
54 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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177 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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63 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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39 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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62 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} + ...
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1answer
36 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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26 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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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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52 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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50 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
122 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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53 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 ...
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1answer
29 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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3answers
60 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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49 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, ...
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34 views

Why does the equilibrium law work mathematically and what does it really mean [duplicate]

For example consider: $$aA + bB \rightarrow pP + nN$$ where $a, b, p$ and $n$ are moles. The equilibrium constant is $$ \frac{[P]^p [N]^n }{[A]^a [B]^b}$$ Where does this come from? I don't ...
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60 views

Does Nitrogen dioxide change colour if we put it in a constant temperature of e.g. 100 kelvin?

The changing of the colour of $\ce{NO2}$ is because of a change in temperature, resp. heating and cooling?
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130 views

Determine the pH of mixture of two weak acids

We've two solutions : Solution 1 $HCOOH$ its concentration is $c_1=10^{-2} mol/l$ and its volume is $v_1 = 50 ml$ and its $pH_1 = 2.9$ Solution 2 $CH_3COOH$ its concentration is $c_2=10^{-2} mol/l$ ...
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65 views

Multiplication of the reaction and Equilibrium constant

$$\begin{align}\ce{2A + 2B &-> 2C }\\ \ce{A + B &-> C}\end{align}$$ Why does the equilibrium constant change? And why the rate of the first reaction square the rate of the second? I ...
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3answers
72 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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84 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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44 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 ...