Question

The equilibrium constant, Kp for the reaction

CO(g) + H2O(g) yields CO2(g) + H2(g)

at 986C is 0.63. A rigid cylinder at that temperature contains 1.2 atm of carbon monoxide, 0.20 atm of water vapor, 0.30 atm of carbon dioxide, and 0.27atm of hydrogen. Is the system at equilibrium.

A. Yes
B. No, the reverse reaction must proceed to establish equilibrium.
C. The starting concentrations of all substances must be known before deciding
D. The volume of the container must be known before deciding
E. No, the forward reaction must be proceed to establish equilibrium

Answer 1

use the pressures given to calculate the reaction quotient, Q. Then compare Q to the given Kp value. If Q < K, equilibrium hasn't been reached (yet). If Q > K, the reaction has gone too far and must reverse itself to restore equilibrium. If Q = K, then the system is at equilibrium.

Answer 2

Thanks a lot. Your answer has confirmed mine