Consider the following reversible reaction carried out at 298 K:
X2(g)⇌2Y(g)Kp=4.0×10−4
A sealed 1.00 L container is initially charged with 0.200 mol of X2(g) and no Y(g).
(a) Write the equilibrium-constant expression for Kp for this reaction.
(b) Using appropriate reasoning rather than a full ICE calculation, estimate whether the equilibrium partial pressure of X2 will decrease by more than 5 % from its initial value once equilibrium is reached. Clearly support your estimate with numerical comparisons that involve the given Kp.
(c) A classmate claims, “Because the equilibrium constant is less than 1, the reaction will never proceed in the forward direction.” Evaluate this claim in the context of your answer to part (b).
(d) Explain how the magnitude of Kp would change, if at all, if the same reaction mixture were compressed to half of its original volume at the same temperature before equilibrium is re-established. Justify your answer.