Question

If [H2]t=0.10 M, [I2]t = 0.20 M and [HI]t = 0.40 M, in the reaction H2(g) + I2(g) \(\rightleftharpoons\) 2HI(g), what is the value of QC?

(a) 8

(b) 4

(c) 2

(d) 1

The question was posed to me in my homework.

This intriguing question originated from Applications of Equilibrium Constants topic in division Equilibrium of Chemistry – Class 11

Answer 1

Correct answer is (a) 8

The best explanation: We know that reaction quotient Qc = [HI]t^2 / [H2]t[I2]t and given that [H2]t=0.10 M, [I2]t = 0.20 M and [HI]t = 0.40 M, So by substituting, we get Qc = (0.40 M x 0.40 M)/(0.20 M x 0.10 M) = 8.0, 8 is the answer.