In the experiment the hydrogen gas is collected in a eudiometer tube over water. If the barometric pressure and the temperature at the time of the experiment are 752.3 mm Hg and 21.6°C, respectively, and the vapor pressure of water at 21.6°C is 19.4 mm Hg, what is the pressure of the hydrogen gas in the eudiometer tube (in mmHg) ?

732.9 mmHg

Explanation:

At the eudiometer tube is the mixture of water and hydrogen gas (H₂), by Dalton's law of the partial pressure, the total pressure of a gas mixture (barometric pressure) is equal to the sum of the partial pressures of the components of the mixture:

Ptotal = Pwater + Phydrogen

752.3 = 19.4 + Phydrogen

Phydrogen = 752.3 - 19.4

Phydrogen = 732.9 mmHg