Hint:Value of equilibrium constant inversely depends on temperature. As we increase the temperature, the value of equilibrium constant decreases and when we decrease the temperature, the value of equilibrium constant increases.
Complete step by step answer:
-The equilibrium constant can be defined as the ratio between the product of molar concentration of the product to that of the product of molar concentration of the reactants with each concentration term raised to a power equal to stoichiometric coefficient in the balanced chemical equation at equilibrium.
From the general chemical equation:
$aA + bB \rightleftharpoons cC + dD$
The equilibrium constant can be given as:
${K_{eq}} = \dfrac{{{{[C]}^c}{{[D]}^d}}}{{{{[A]}^a}{{[B]}^b}}}$
-From this equation we may think that the equilibrium constant depends on actual quantities of reactant but in real, the initial concentrations of both products and reactants evolve such that equilibrium constant is satisfied. If the equilibrium constant is large then the products are favored at equilibrium and if equilibrium constant is small then the reactants are favored at equilibrium. Hence, the equilibrium constant does not depend on quantities of product and reactants.
-The equilibrium constant in terms of standard Gibbs free energy can be given as:
${K_{eq}} = {e^{\dfrac{{ - \Delta G^\circ }}{{RT}}}}$
Where, $T = $temperature
$R = $ gas constant
$\Delta G^\circ = $ standard Gibbs free energy
-As we can see here that equilibrium constant depends on temperature. As the temperature increases then the value of equilibrium constant decreases and when temperature decreases then equilibrium constant increases.
Hence, option C.) is the correct answer.
Note:
Always remember that equilibrium constant is not affected by change in concentration, pressure, catalyst and inert gas addition but equilibrium constant is only affected by the temperature.
