Question

Consider the water gas equilibrium reaction, $C ( s )+ H _{2} O ( g ) \rightleftharpoons CO ( g )+ H _{2}( g )$ Which of the following statements is true at equilibrium?

• A. If the amount of $C(s)$ is increased, less water would be formed
• B. If the amount of $C(s)$ is increased, more $CO$ and $H_2$ would be formed
• C. If the pressure on the system is increased by halving the volume, more water would be formed
• D. If the pressure on the system is increased by halving the volume, more $CO$ and $H_2$ would be formed

Answer 1

Answer: (C)

If the pressure on the system is increased by halving the volume, more water would be formed

Answer 2

$K = \frac{\left[CO\left(g\right)\right]\left[H_{2}\left(g\right)\right]}{\left[H_{2}O\left(g\right)\right]}$
Concentration will increase, on halving the volume. There are two terms in numerator. So to keep K constant, concentration of $[H_2O]$ should increase much more.