Question

Equilibrium constant depends upon
A.The actual quantities of reactants and products
B.The presence of a catalyst
C.Temperature
D.The presence of inert material.

Answer 1

Hint: This question requires knowledge on the reaction equilibrium. In a reversible reaction, there comes a stage when the rate of the forward reaction is equal to the rate of the backward reaction and a dynamic equilibrium is developed between the two sides. This is called reaction equilibrium.

Complete step by step answer:
Consider a reversible reaction as follows:
$aA + bB \rightleftharpoons cC + dD$
In this reaction, when the rate of the forward reaction is equal to the rate of backward reaction, then we can write that,
Rate of the forward reaction = ${k_1}{\left[ A \right]^a}{\left[ B \right]^b}$
And, rate of the backward reaction = ${k_2}{\left[ C \right]^c}{\left[ D \right]^d}$
At equilibrium, ${k_1}{\left[ A \right]^a}{\left[ B \right]^b}$=${k_2}{\left[ C \right]^c}{\left[ D \right]^d}$$ \Rightarrow \dfrac{{{k_1}}}{{{k_2}}} = {\dfrac{{\left[ A \right]}}{{{{\left[ C \right]}^c}}}^a} \times \dfrac{{{{\left[ B \right]}^b}}}{{{{\left[ D \right]}^d}}}$
1.The ratio of $\dfrac{{{k_1}}}{{{k_2}}}$is known as the Equilibrium Constant of the reaction of ${K_c}$. The increase in the reactant concentration increases the rate of forward reaction and the equilibrium is shifted to the left while an increase in the product concentration shifts the equilibrium to the right.
2.The catalyst does not affect the state of equilibrium of a gas, it only speeds up the reaction. And it speeds up both the forward as well as the backward reactions.
3.How the change in temperature will affect the reaction depends on the reaction being endothermic or exothermic. For endothermic reactions as heat is the reactant here, an increase in temperature should shift the equilibrium to the product side while a decrease should shift it to the reactant side. On the other hand, for exothermic reactions, increase in temperature causes backward reaction while decrease in temperature causes increase in the forward rate.
4.The presence of any inert gas or compound does not cause any change in the equilibrium as the reaction on both the sides remains unaffected by its presence.

So the correct answer is option (C)

Note: Le Chatelier’s principle predicts the behaviour of an equilibrium system. According to this, if a dynamic equilibrium is disturbed by changing the equilibrium, it will adjust itself accordingly to restore the equilibrium back. There are different factors that can affect this reaction equilibrium, such as Temperature, volume, pressure, and the change in the concentration of the reactants and the products.