In case of the decomposition of hydroiodic acid (2H$$I$$ ⇋ H₂ + $${{I_2}}$$), addition of H₂ (at equilibrium condition) will

A. Increase the partial pressure of $${{I_2}}$$

B. Decrease the partial pressure of H$$I$$

C. Diminish the degree of dissociation of H$$I$$

D. None of these

Answer: Option C

Solution(By Examveda Team)

Lechalters principle: Actually for an equilibrium reaction on increasing the reactant concentration the equilibrium shifts towards the right and therefore the reactants gets more dissociated and products concentration increases but here we are increasing the product $$\left( {{H_2}} \right)$$  concentration so the equilibrium shifts towards left and increases the formation of $$2HI$$  there by decreasing the dissociation of $$HI$$.