Questions tagged [equilibrium]
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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Derivation of the Van 't Hoff equation
I was reading the paper Relaxation Kinetics of Ferric Thiocyanate (Goodall et. al, 1972) and I came across the passage
Reaction (1) is the simplest representation of the equilibrium between ferric ...
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Determining whether precipitation will occur or not and finding the concentration of a specific ion in a solution
The Ksp value of AY2 = 9.148 x 10^-2. I am having problem with calculating the concentration of ions. And without the correct concentration I can't find the Qsp/Kip so I'm stuck without them I can't ...
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Can an electrode run out of the active species?
I have a background in solid state physics but am new to electrochemistry. I have been following the example of a physical chemistry (Mortimer) book that looks an electrochemical cell with a hydrogen ...
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Why is it that in a buffer solution the equilibrium concentrations may be assumed to be the initial concentrations? [duplicate]
Considering the Henderson–Hasselbalch equation,
$$\text{pH} = \text{p}K_a + \lg \frac{[\ce{AcO⁻}]} {[\ce{AcOH}]}$$
$$\text{p}K_a = \lg \frac{[\ce{AcO⁻}][\ce{H⁺}]} {[\ce{AcOH}]}$$
Why are the values ...
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Temperature-dependent pressure equilibrium constant of the heterogeneous water-gas shift reaction
In the course of my research, it became necessary to perform thermodynamic calculations involving chemical reactions. One of the chemical reactions is the heterogeneous water-gas shift reaction
$$\ce{...
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Solubility of SrF2 in aqueous solution of NaF
This might be really simple question but I have no idea how to proceed to solve such kind of question.
The solubility product of $\ce{SrF2}$ in water is $\pu{8E-10}$. Calculate its solubility in 0.1M ...
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How do I determine temperature and pressure rise whenever mols of gases are added in a isolated room?
Let's consider a fully isolated room, no gas or heat flowing from it.
We consider gases ($\ce{O2,N2,CO2}$) to follow the ideal gas law, and no chemical reaction occurs between them.
Pressure $p$, ...
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Change in Gibb's free energy at equilirbrium [duplicate]
I know the basic relation that ΔG=ΔG⁰+RTln(Q) where Q is the reaction quotient, my doubt is that if Q=1 at equilibrium then ΔG=ΔG⁰ but will ΔG=0 or ΔG≠0? As far as I know, generally at equilibrium Q=...
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Equilibrium Solubility of CO2 in Aqueous Solution and its Dependence on H3O+ Concentration
The equilibrium solubility of $\ce{CO2}$ in an aqueous solution is given by three chemical reactions:
$$
\begin{align}
\ce{CO2(g) &<=> CO2(aq)}\label{rxn:R1}\tag{R1}\\
\ce{CO2(aq) + H2O &...
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What does it mean Keq=1?
I’m struggling with a chemistry question related to equilibrium in a reaction. I don’t understand the meaning of $K_\text{eq} = 1$. After some research I found that when $K_\text{eq}$ is 1 it means ...
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Which xylenes, if any, are immiscible with DMSO?
"Xylene" is reported to be immiscible with dimethyl sulfoxide (DMSO), according to a few solvent miscibility tables found online (chart 1, chart 2, chart 3). I have tried to locate some ...
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Non-elementary reactions: Relationship between kinetic and equilibrium constant
As far as I understand, the equation for a kinetic equilibrium is always the same, and is given by:
$$K = \frac{\text{concentration of products}^{p}} {\text{concentration of reactants}^{r}}$$
Where $p$...
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Why can we use stoichiometric coefficients in the equilibrium-constant expression? [duplicate]
I just studied the chapter on chemical kinetics on Coursera, wherein I was repeatedly admonished not to use the stoichiometric coefficients in the rate law formula. I was told that this formula has to ...
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Gibbs free energy versus reaction progress plots
I am trying to make sense of these two graphs. They appear to have similar axes, yet display different curves.
Please let me know if this understanding is correct:
In the top image (x-axis = "...
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Difference in salinity and/or sugar content: Does it have a name? [closed]
Let's say that I put a tea infuser full of high-salt and/or high-sugar content, into a tea pot full of fresh water. I know that the salt and/or sugar will move from the infuser to the tea pot until ...
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Pressure before equilibrium = Pressure during equilibrium?
For example, let's say we have the equation $$\ce{PCl_3(g) + Cl_2(g) -> PCl_5(g)},$$ and the temperature is held constant.
Would the pressure in the container when equilibrium is reached be greater ...
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What are the dissociation constants of hydronium and hydroxide ions? [duplicate]
Context
The answer to How to calculate Ka for hydronium and Kb for hydroxide?, water was regarded as solvent once and base (or equivalently acid) once while citing Reference 1 (1986) and made no ...
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If Qc> Kc how can forward reaction can take place
If Qc>Kc then there will be a net backward reaction but still forward reaction will take place. My problem is if Qc>Kc forward reaction will become non spontaneous right. So how can that happen, ...
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What if kc=1 will reactants concentration equals to product concentration [closed]
I read a book, it says if kc=1 it mean reactant concentration equals to product concentration at equilibrium. But I'm wondering that in kc expression we dont just use concentration of an element we ...
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Change of equilibrium constant with respect to temperature
Suppose we have an arbitrary chemical reaction $A+B\rightleftharpoons 2C+D$ and its equilibrium constant at two temperatures $T_{1},T_{2}$ are $k_{1},k_{2}$. We can relate them as
$$\log\frac{k_{2}}{...
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Chemical Equilibrium and Sponteneity
Consider the reaction $$\ce{N2O4 <=> 2 NO2}.$$ The forward direction of this reaction is non-spontaneous and under standard conditions $\Delta G^\circ = \pu{4.76 kJ/mol}$. Suppose we begin with $...
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Determine the pKa of a diprotic acid by titration (if pKa1 is similar to pKa2)
Determining the acidity constants of a diprotic acid (in my case, tartaric acid) by titration with NaOH and pH-meter is not possible if pKa2 - pKa1 < 2.
This is because there are no "pH jumps&...
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How does enzyme velocity decrease as reaction quotient approaches equilibrium constant?
I created a simulation which approximates molecule concentrations in a cell. One part of it are enzymes that can catalyze pre-defined reactions, e.g. $\ce{A <=> B}$.
I based the kinetics for ...
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For radical polymerization reactions, azobis(isobutyronitrile) (AIBN) can also be used as a radical initiator
Draw the mechanism of radical formation if you know that N2 is formed as a by-product.
The solution they give us is
I know what radical polymerization is. The free electron of a molecule binds with ...
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Can ΔG = ΔG° + RT ln Q be used to calculate K at different temperatures?
Specifically, can $\Delta G=\Delta G^{\circ}+RT \ln Q$ be used to calculate reaction quotients if we choose T to be a different temperature than the one provided by ΔG°?
For example, suppose that we ...
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Do complexes of a metal distribute in between the water and an organic compound layer?
My original question is one that is stated in the title, and I also have some side questions too.
I came across this question where you have a CuSO4 aqueous solution. Then you take an Ammonia aqueous ...
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How do metal hydrides behave in a non-hydrogen closed system?
I am curious about the fundamentals of metal hydrides and how adsorption/desorption works in non-hydrogen systems. My understanding is that the atom ratio M/Hx of the metal hydride is a function of ...
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How to calculate pH of a 0.1 M solution of ammonium bicarbonate considering simultaneous equilibrium along with hydrolysis?
We need to calculate the $\ce{[H+]}$ of 0.1M $\ce{(NH4+)(HCO3^-)}$ given the $\ce{k_b(NH4OH), k_{a_1}(H2CO3), k_{a_2}(HCO3^-)}$
The hint tells me to directly use the result $\ce{[H+]=\sqrt{k_{a_1}(\...
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Successive deprotonation - how far can it go?
It has been written that among the equilibria of the dissolution of $\ce{SO_2}$ in water, the dissociation of sulphur dioxide into $\ce{HSO_3^-(aq) + H_3O^+(aq)}$ is a complete dissociation. See the ...
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What is the basis for the relationship of Gibbs energy and extent of reaction shown in this graph?
How this graph of Gibbs free energy between reaction coordinate is made because because
∆G = ∆G° + RT ln Q
and since ∆G° and T is constant hence the graph should be like that of ln(x)?
Source: https:/...
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