Zinc metal is added to hydrochloric acid to generate hydrogen gas, which is collected over a liquid whose vapor pressure is the same as pure water at 20.0°c (18 torr). the volume of the gas mixture is 1.7 l and its total pressure is 0.810 atm. determine the partial pressure of the hydrogen gas in this mixture.

The partial pressure of the hydrogen gas is 0.786 atm

Explanation:

In this case, the gas mixture contains the vapor from the liquid, and hydrogen gas. Before we do any calculations, we need to convert 18 torr into atm:

Then we use the equation of Dalton's law, which states that the total pressure of a gas mixture is equal to the sum of the partial pressure of its components:

Where is the total pressure, is the partial pressure of hydrogen, and is the partial pressure of the vapor of the liquid.

Replacing the data we know:

0.810 atm= + 0.0237 atm

= 0.786 atm