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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Does the added component (intended to disturb equilibrium) always ends up being more than the original amount, in the new equilibrium?

The title can be a little unclear. But what I am basically saying is say we add a reactant to a reaction to push the reaction forward toward the product side, that reactant which was increased in ...
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1answer
28 views

Finding equilibrium concentrations, trouble simplifying equation

For $\ce{CO (g) + H2 (g) <=> CH2O (g)}$ with Kc = 0.068 @ 273K initial concentrations being [CO] = 1.25M, [H2] = 2.00M, [CH2O] = 1.00M I did $(1.00)/((1.25)(2.00)) = 0.4$, which is more then ...
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22 views

How to calculate the sulfanediide concentration at equilibrium in a saturated hydrogendisulfide solution at pH 6? [on hold]

What is the $\ce{S^{2-}}$ concentration in a saturated solution (0.10 M) of $\ce{H2S}$, in which the pH has been adjusted to 6.00 by the addition of $\ce{HCl}$? For $\ce{H2S}$, $K_{a1} = 1.1 \cdot ...
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1answer
22 views

Finding Kp at another temp with /\Hrxn [on hold]

Took a pic of the paper I tried it on it on, has the exact problem description written at top, and what I tried. Figured that would be easier then typing all that. The answer is supposed to be 2.0.
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2answers
46 views

How to calculate pH of a solution with two dominant equilibria?

Say you have acid X for which $K_a(X)$ = 1E-7 and acid Y for which $K_a(Y)$ = 0.8E-7. In separate solutions, it would be easy to calculate $[H^+]$ because there would be only one dominant equilibrium. ...
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1answer
52 views

How to calculate the concentration of NO at equilibrium?

$\ce{N2(g) + O2(g) <=> 2NO(g)}$, $K_c = 4.1 \cdot 10^{-4} (T=2000~^\circ\mathrm{C})$ What is $\ce{[NO]}$ when a mixture of $0.20~\mathrm{mol}$ $\ce{N2(g)}$ and $0.15~\mathrm{mol}$ ...
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26 views

What is the difference between K and Kp in the equilibrium equation?

In this equilibrium equation, $$K = K_p\cdot (\mathcal{R}T)^{-\Delta n}$$ what does $K$ represent in comparison to $K_p$? It seems to me that they'd both be equilibrium constants, but how are they ...
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0answers
48 views

Equilibrium Concentrations? [closed]

Into a cannister of volume $1L$, $256~ g$, of $\ce{SO_2}$ and $64~ g$ of oxygen are inserted; at $1100~K$ an equilibrium exists... The reaction: $$\ce{2 SO2 (g) + O2(g) <=> 2 SO3(g)}$$ Since ...
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1answer
325 views

Are all strong bases alkalis?

In my text book, it says that strong bases are alkalis because they fully dissociate in aqueous solution. But I'm not too sure of this. Can you not have a weak alkali? And can you not have a strong ...
2
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1answer
46 views

Solid and Liquid Equilibrium [duplicate]

I understand why solids and liquids are not included in the $K_{eq}$ expressions. However, I'm wondering what the $K$ value for a reaction involving only solid or liquid reactants and products looks ...
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1answer
31 views

How to calculate the equilibrium concentration from initial concentrations of the substrates? [on hold]

Consider the following equilibrium: $$\ce{2NOCl~(g) <=> 2NO~(g) + Cl2~(g)}$$ with $K = 1.6 \cdot 10^{–5}$. $1.00~\mathrm{mol}$ of pure $\ce{NOCl}$ and $0.989~\mathrm{mol}$ of ...
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2answers
99 views

How can pKas differ across similar protons of the same atom?

For example, citric acid has three acidic protons, all of which are carboxylic acids. Despite being part of the same functional groups, they all have very different pKas. Why (and how?) is this?
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1answer
18 views

Does a change in partial pressure for a gas-solid reaction, changes the equilibrium?

This is my reaction, $$\ce{Cd (g) + 1/2 Te2 (g) -> CdTe (s)}.$$ Considering the solid CdTe, $$K = P_{\ce{Cd}}^\mathrm{Eq}\cdot \left(P_{\ce{Te}}^\mathrm{Eq}\right)^{\frac{1}{2}}$$ I only have ...
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1answer
37 views

Spontaneity of reversible chemical reactions - Both sides?

Does the reversibility of a chemical reaction make it spontaneous from both sides also? (i.e.: forward & backward reactions) If not then is there any relationship between $\Delta G$ of forward and ...
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2answers
49 views

Can we force a reversible reaction in equilibrium to become a “complete” one? If so, will the equilibrium constant change?

It's said about reversible reactions that they never go to completion & I know that's because in reversible reactions, the mixture obtained in equilibrium is more stable than the extremes (i.e. ...
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1answer
21 views

What is buffer capacity and how can a buffer “run out”?

I'm a little confused on something: A buffer has a certain capacity and then runs out. But, if the buffer is given by: $$\ce{A- + H2O <=> HA + OH-},$$ when the $\ce{A-}$ reacts with the water, ...
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2answers
37 views

Why is it that weak bases usually contain a Nitrogen?

Why do weak bases usually contain a nitrogen, I know there are two electrons on top for a bond of H but why is it mostly nitrogen? I know there are other elemental bases too but why do I keep seeing ...
2
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1answer
30 views

Why don't ions have one equilibrium potential? (Nernst equation)

I know that equilibrium potentials are dependent on the ratio of ion concentrations inside and outside of the cell and temperature. I also know that the equilibrium potential is reached when there is ...
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2answers
425 views

What's the pH of Vinegar when it generally contains 5% Acetic acid?

Vinegar generally contains 5% Acetic acid. We would expect the pH of vinegar to be approximately: a. 0 b. 3 c. 7 d. 9 e. 12 I don't have the key for this question, so I ...
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1answer
28 views

What is the S2- in 0.10 M hydrogen sulfide?

I found this question in one of the problem sets and I decided to try it, I keep getting 9.1E-8 as the answer and I thought this since this is a diprotic acid and I made two equations and I keep ...
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2answers
243 views

Why is the second reaction being neglected?

If we want to find the concentration of $\ce{H+}$ ions at equilibrium when a weak conjugate base such as $\ce{C2H3O2-}$ added to water, why do we take the conjugate base reaction for calculation i.e ...
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1answer
40 views

How to calculate the pH of a citric acid solution after adding magnesium oxide? [closed]

$4.03~\mathrm{g}$ ($0.100~\mathrm{mol}$) of magnesium oxide is added to $100~\mathrm{mL}$ of a saturated ($4.00~\mathrm{mol\cdot L^{–1}}$) solution of citric acid. Calculate the pH of the resulting ...
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1answer
27 views

Equilibrium Concentrations of Products/Reactants

Does increasing the concentration of reactants mean the equilibrium concentration of the products will be greater (than the concentration of the reactants?)
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25 views

What's the name of the problem of finding equilibrium concentrations?

Is there any specific name of the problem of finding equilibrium concentrations with known equilibrium constants and initial concentrations? Would it be appropriate to call it "direct equilibrium ...
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58 views

Strong and Weak Acids/Bases

I'm so confused... $\ce{HClO}$ is a weak acid. then why is its conjugate base, $\ce{ClO-}$, a weak base in water? shouldn't they be inversely proportional? shouldn't $\ce{ClO-}$, be a strong base? ...
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1answer
57 views

How to calculate the concentration of all relevant species in a buffer of a given pH?

You prepare $1.0~\mathrm{L}$ of a $0.25~\mathrm{M}$ acetic acid solution with a final $\ce{pH}$ of $6.0$. What are the molar concentrations of all relevant acetic acid species ($[\ce{HA}]$ and ...
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2answers
53 views

What are the effects of adding water to a system at equilibrium?

Given the reaction $\ce{NaCl~(s) <=> Na+~(aq) + Cl^{-}~(aq)}$. $\ce{NaCl}$ is added to water and equilibrium is reached. Does the reaction shift to the left/right/not shift at all if more ...
3
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2answers
129 views

reference states for activities

I wanted to ask clarifications about a passage in Atkin's physical chemistry book, chapter 9, in the paragraph 9.2 description of equilibrium. For studying equilibrium of a reaction, where $\nu_i$ ...
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1answer
43 views

Should the liquid be included in Kc expression?

Should the concentration of liquid water be included in the Kc expression for the following reaction: $$\ce{2 NO2{(g)} + 7 H2{(g)} \rightarrow 2 NH3{(g)} + 4 H2O{(l)}}$$ if water is liquid and all the ...
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2answers
66 views

Dynamic equilibrium - effect of adding inert gas [duplicate]

Well consider the reaction $A + B ⇌ C$ Adding inert gas to a container where this reaction is taking place will increase the pressure of the system. In accordance with Le Chatelier's Principle, the ...
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3answers
66 views

Thought Experiment on Boiling

In this thought experiment, let’s consider the surrounding to be air that is composed of entirely water vapor (no other species like $\ce{O2}$ and $\ce{N2}$ are present). The surrounding is infinitely ...
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1answer
47 views

Why is it possible, that an equilibrium shifts?

So in class, I've learned about Equilibrium. So it is basically when the rate of the reverse and the forward reaction are the same. So I was like that sounds pretty easy, I can understand this. And ...
2
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1answer
68 views

How to find and use the Clausius-Clapeyron equation

I know how to get the equation from the Clapeyron equation but I have a question regarding a the integration along a phase boundary and a small step in the derivation that I will make clear when I ...
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1answer
45 views

Acid dissociation constant and equilibrium constant

What is the relationship between acid dissociation constant and equilibrium constant for an acid's reaction with water? If we have this reaction: $\ce{CH3COOH + H2O → CH3COO- + H3O+}$ I would ...
3
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1answer
51 views

Why do acids usually completely react with bases?

When a neutralisation reaction happens, for example, $ 100 \mathrm{mol.l}^{-1}$ of $\ce{HCl }$ with $\mathrm{100 mol.l}^{-1}$ $\ce{NH_3}$, why does all of the base and acid get converted to salt ? Why ...
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1answer
24 views

Equilibrium Constant of a Salt knowing the solubility

Calculate the equilibrium constant in $\ce\\M ^ 3$ of the heterogeneous system in aqueous solution: $\ce{CaF2 \leftrightarrows Ca^{2+} + 2F-}$ Knowing that the solubility of the salt is $15.9 ...
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1answer
49 views

Why does the ionic product of water remain constant after addition of non-neutral solute?

In my textbook, it is given that the ionic product of water $K_w$ remains constant even when a non-neutral solute such as an acid is added to it. $$K_w=\ce{[H3+O][OH- ]}$$ When a strong acid is added ...
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18 views

Reaction Rates & Eqiulibrium [duplicate]

So I have a quick question about some concept I have watched in a video, it is illustrated as follows. $$\ce{A + B <=> C + D}$$ So what the video is saying is that if you increase $\ce{A}$ ...
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1answer
62 views

Neutralizing sulfur-like smells in car

A full bottle of jewelry cleaning (links product and material safety data sheet below) broke in my car and went unnoticed for a few days. Now the car has a sulfur-like smell whenever I go into the ...
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111 views

Predict the standard potential at 310 K for the cell constructed from the hydrogen electrode and metal-insoluble salt electrode

I've run into trouble on this question Predict the standard potential at 310 K for the cell constructed from the hydrogen electrode and metal-insoluble salt electrode $\ce{Ag(s)|AgCl(s)|Cl-}$. ...
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1answer
39 views

Stuck with derivation of the integrated rate equation for a pseudo first order equilibrium reaction

I was reading about the integrated rate law. However I have problems to follow the solution. I have an equilibrium reaction: [A]+[B]=[AB] with forward and back reaction. I approximate the ...
3
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1answer
75 views

Where does this equation for the activity in the gas phase equilibrium between N₂, H₂ and NH₃ come from?

I have a question with Equilibrium Constant. I understand that for a reaction in equilibrium $aA +bB \rightleftharpoons cC +dD$ $$K_c= \frac{[C]^c[D]^d}{[A]^a[B]^b}$$ and $K_p$ is just using the ...
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2answers
262 views

What is the difference between “reaction in both directions” and “equilibrium”?

According to the Wikipedia page on Chemical Equations: Symbols are used to differentiate between different types of reactions. To denote the type of reaction: "$=$" symbol is used to denote a ...
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2answers
39 views

Is this reaction at equilibrium?

The following equilibrium occurs: $$\ce{2 NOCl(g) <=> 2 NO(g) + Cl2(g)}$$ A gaseous mixture of $\ce{NOCl}$, $\ce{NO}$ and $\ce{Cl2}$ is put in a container. After a few minutes it is found that ...
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1answer
34 views

In the following reaction, will the ratio between substances be 3:1?

In the reaction $$\ce{3 C2H2(g) <=> C6H6(g)}$$ will the ratio of $\ce{[C2H2(g)]}$ to $\ce{[C6H6(g)]}$ at equilibrium be 3:1? How is the mole ratio related to the equilibrium (or lack thereof) ...
3
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1answer
51 views

Which has a greater entropy?

Which of the following has greater entropy? a. $\ce{CH3COOH~ (aq)}$ or b. $\ce{CH3COO^{-}~ (aq) + H+~(aq)}$ They are both in the same state, and have the same number of particles.. so how do ...
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1answer
59 views

Will room-temperature water in a sealed flask evaporate?

Some liquid water is present inside a sealed flask at room temperature. Is water evaporating, and is the system at equilibrium? First of all, can water evaporate in a sealed flask at room temperature? ...
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1answer
46 views

Can there be more than one combination of reactant/product concentration for a specific equilibrium constant?

For an elementary reaction like $$\ce{A + B -> AB},$$ $$K_{c} = \frac{\ce{[AB]}}{\ce{[A][B]}}$$ and $$\frac{\mathrm{d}\ce{[AB]}}{\mathrm{d}t} = k\ce{[A][B]}.$$ If I let the reaction reach ...
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1answer
20 views

Exothermic reactions at high temperature and the chemical equilibrium

Why are many exothermic reactions, like Haber process, conducted at high temperature, thus their unfavourable equilibrium position?
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1answer
39 views

Trouble to predict the effect of pressure and temperature for a reaction in equilibrium

I have trouble to predict the effect of decreasing pressure and increasing temperature on the reaction $\ce{N2 + 2O2 <=> 2NO2}$. Increasing temperature caused this reaction to shift in the ...