Question

Consider the following reaction where Kp = 2.01 at 500 K: PCl3(g) + Cl2(g) PCl5(g) If the three gases are mixed in a rigid container at 500 K so that the partial pressure of each gas is initially one atm, what will happen? Indicate True (T) or False (F) for each of the following: T 1. A reaction will occur in which PCl5(g) is consumed. T 2. Kp will decrease. F 3. A reaction will occur in which PCl3 is produced. F 4. Q is greater than K. F 5. The reaction is at equilibrium. No further reaction will occur.

Answer 1

Explanation:

Kp remains constant (if T=const.).

If Q<Kp, more reactants are consumed (the direct reaction is in progress). If Q>Kp the reverse reaction is in progress (the products are consumed).

1. A reaction will occur in which PCl5 (g) is consumed

A. If Kp > Qp  then 1,2,3 and 5 are F.  4 is T

B. Kc > Qc then 1,3 are T. 2,4,5 are F.

C. Qp > Kp then 1.3.4 are T. 2,5 are F.