Question

A certain amount of H$_{2(g)}$ and I$_{2(g)}$ are sealed in a 4L container and kept at 600K to attain equilibrium. K$_C$ for the reaction, H$_{2(g)}$ + I$_{2(g)} \rightleftharpoons$ 2HI\(_{(g)}\) at 600K is 64. If the equilibrium concentration of HI\(_{(g)}\) is 0.08M, what are the equilibrium concentrations of H$_{2(g)}$ and I$_{2(g)}$ at the same temperature?

• A. 0.02 M
• B. 0.01 M
• C. 0.03 M
• D. 0.04 M

Hint:

To avoid big decimal math, take the square root of both sides of the equation first:
\(\sqrt{64} = \sqrt{\frac{[HI]^2}{x^2}} \implies 8 = \frac{0.08}{x} \implies x = \frac{0.08}{8} = 0.01\). This is much cleaner!

Answer 1

The Correct Option is B