Question

The thermal dissociation equilibrium of $CaC{O}_3\left(s\right)$ is studied under different conditions.
$CaC{O}_3\left(s\right)\rightleftharpoons CaO\left(s\right)+C{O}_2\left(g\right)$
For this equilibrium, the correct statement(s) is (are) :

• A. $\Delta H$ is dependent on $T$
• B. $K$ is independent of the initial amount of $CaC{O}_3$
• C. $K$ is dependent on the pressure of $C{O}_2$ at a given $T$
• D. $\Delta H$ is independent of the catalyst, if any

Answer 1

The correct option is C $K$ is dependent on the pressure of $C{O}_2$ at a given $T$

Option $\left(C\right)$ is correct.

$K$ is dependent on the pressure of $C{O}_2$ and $CaC{O}_3$ at a given $T$.

When a system at equilibrium undergoes a change in pressure, the equilibrium of the system will shift to offset the change and establish a new equilibrium. The system can shift in one of two ways:

Toward the reactants (i.e. in favour of the reverse reaction)

Toward the products (i.e. in favour of the forward reaction)

The effects of changes in pressure can be described as follows (this only applies to reactions involving gases):

When there is an increase in pressure, the equilibrium will shift towards the side of the reaction with fewer moles of gas.

When there is a decrease in pressure, the equilibrium will shift towards the side of the reaction with more moles of gas.