First, we need to find the partial pressure of the hydrogen gas. We can do this by subtracting the vapor pressure of water from the atmospheric pressure.
$P_{H_2} = P_{atm} - P_{H_2O} = 748 \,\text{mmHg} - 18.7 \,\text{mmHg} = 729.3 \,\text{mmHg}$
Show more…