If the reaction starts with a mixture of PCl5, PCl3 and Cl2 at pressures of 0.820 atm, 1.322 atm and 0.911 atm respectively, is the reaction at equilibrium

The reaction is not in equilibrium

Explanation:

For the reaction:

PCl₅ ⇄ PCl₃ + Cl₂

Equilibrium constant, Kp, is defined as:

When this ratio is = 0.497, the reaction is in equilibrium. Replacing the pressures of the problem, reaction quotient, Q, is:

As Q ≠ Kp, the reaction is not in equilibrium

To reach the equilibrium, the reaction will shift to the left producing more reactant and decreasing amount of products.

the answers would be

the first one and the second one