The following two reactions:
i. `PCl_(5)(g) hArr PCl_(3)(g)+Cl_(2)(g)`
(ii) `COCl_(2)(g) hArr CO(g)+Cl_(2)(g)`
are simultaneously in equilibrium in a container at constant volume. A few moles of `CO(g)` are later introduced into the vessel. After some time, the new equilibrium concentration of

Options

A. `PCl_5` will remain unchanged
B. `Cl_2` will be greater
C. `PCl_5` will become less
D. `PCl_5` will become greater

Answer

C

Explanation

If CO is added `2^(nd)` equilibrium will proceede in the backward direction and concentration of `Cl_2` will decreases This `Cl_2` will be further formed by the decomposition of `PCl_5`