All Questions
Tagged with equilibrium kinetics
115
questions
33
votes
4
answers
69k
views
Why are solids and liquids not included in the equilibrium constant? What about in a reaction rate calculation?
Take for instance the reaction
$$\ce{H2(g) + I2(s) <=> 2HI(g)}$$
The equilibrium constant would not include the solid $\ce{I2}$, but why is this? I have read that its concentration is a ...
- 3,256
26
votes
4
answers
4k
views
Relation between chemical kinetics and chemical equilibrium
In my chemistry book, the law of chemical equilibrium is derived from the law of mass action:
For a reversible chemical reaction $$\ce{aA +bB\rightleftharpoons cC + dD}$$ where $a$, $b$, $c$ and $d$ ...
- 5,685
21
votes
4
answers
27k
views
Why are equilibrium constants unitless?
I haven’t quite reached the point where I can read a full-fledged text on chemical kinetics and thermodynamics yet, so bear with me, please.
I’m wondering why a value like $K_\text{eq} = \frac{[\ce{...
- 831
20
votes
1
answer
619
views
Can a multi-species system oscillate around equilibrium?
In reading about chemical oscillations such as those that occur in the Belousov–Zhabotinsky reaction (BZ), it's often reported that these reactions were initially not taken seriously, because of a ...
- 1,661
19
votes
2
answers
30k
views
Is there a difference between equilibrium and steady state?
The term equilibrium is used in the context of reversible reactions that reach a point where concentrations no longer change. The term steady-state is used in enzyme kinetics when the concentration of ...
- 41.2k
15
votes
1
answer
2k
views
Can a zeroth order reaction be reversible?
After recently studying about chemical equilibrium, I was convinced that the forward and backward reaction rates meet each other at equilibrium.
However thinking about zeroth order reaction annoyed ...
- 161
14
votes
2
answers
1k
views
What is the molecularity of a reversible reaction?
I know that the definition of molecularity of a reaction is number of species reacting in an elementary step. But considering the theory of microscopic reversibility for elementary reactions, each ...
- 141
13
votes
3
answers
7k
views
How is it that the equilibrium constant does not depend on the mechanism?
For a reaction of the form
$$\ce{aA + bB <=> cC + dD}$$
the equilibrium constant is
$$K_c=\frac{[\ce{C}]^c[\ce{D}]^d}{[\ce{A}]^a[\ce{B}]^b}$$
regardless of the mechanism of the reaction. ...
- 1,201
9
votes
3
answers
935
views
Why is the equilibrium constant defined that way intuitively?
Suppose we have chemical equation: $$\ce{ aA + bB <=> cC + dD }$$
then equilibrium constant is defined: $$K=\frac{[C]^c[D]^d}{[A]^a[B]^b}$$
but why don't we define it as: $$K=\frac{cd[C][D]...
- 199
8
votes
4
answers
833
views
Deriving kinetic equations for reversible reactions
Problem
Given the reaction $\ce{A <=>[$k_\mathrm f$][$k_\mathrm b$] B}$ with rate constants $k_\mathrm f = \pu{4E-2 s-1}$ and $k_\mathrm b = \pu{10^{-2} s-1}$. Initially, $\pu{2 mol}$ of $\ce{A}...
- 1,817
8
votes
3
answers
80k
views
Changes in which factors affect both the rate and the rate constant of a first order reaction?
Changes in which factors affect both the rate and the rate
constant of a first order reaction?
I. temperature
II. concentration
(A) I only (B) II only
(C) Both I and II (D) ...
- 3,256
7
votes
2
answers
247
views
first-order binding kinetics with multiple identical binding sites
I have beads in solution at concentration $B$ which have $N$ independent binding sites for a single target molecule at concentration $T$. $T$ is small compared to $B$, so most beads will probably not ...
- 173
7
votes
1
answer
126
views
Arterial blood CO2 content, division and partial pressure
My lecturer cites Boron and Boulpaep's Medical Physiology (2nd edition) for the following claims:
the total $\ce{CO2}$ content of arterial blood is $26.4$ mmol/L or $48\%$ v/v (not sure if these ...
- 477
6
votes
1
answer
635
views
Equilibrium constant for a solid-solid equilibrium
Suppose there are two equations:
$$
\begin{align}
\ce{A(s) &<=> B(g) + C(s)} &\quad &K_1 \tag{R1}\\
\ce{B(g) &<=> D(s) + E(s)} &\quad &K_2 \tag{R2}
\end{align}$$
...
- 487
6
votes
1
answer
159
views
Question about relation between two time constants
I am not a chemist, but a neuroscientist, so bear with me. I have struggled with this problem for over a week now and have realized it's a chemical question. I'll try to explain it so no neuroscience ...
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