Answer to Question #202799 in Chemistry for Shaza Shihadeh

Question

For the reaction 2O (g) ⇌ O2 (g), it has an equilibrium constant (K) of 1.5.

a) If at a certain time, the concentration of O is [O] = 0.5M and concentration of O2 is

[O2] = 0.8M, what is the reaction quotient (Q)?

b) Based on your answer in part a, will the reaction proceed forward or reverse? Why?

Answer 1

The reaction quotient equals:

Q = [product] / [reactant] = [O₂] / [O]² = 0.8 / (0.5)² = 3.2

From here, Q = 3.2 and K = 1.5. Since Q > K, product > reactant and the reaction shifts left (proceeds reverse).