Question

When a chemist collects hydrogen gas over water, she ends up with a mixture of hydrogen and water vapor in her collecting bottle If the pressure in the collecting bottle is 97.1 kilopascals and the vapor pressure of the water is 3 2 kilopascals, what is the partial pressure of the hydrogen?

Answer 1

Answer: 93.9 kPa

Explanation: According to Dalton's law, the total pressure of a mixture of gases is the sum of individual pressures exerted by the constituent gases.

`p_(total)=p_A+p_B`

Thus
`p_(total)=p_(H_2O)+p_(H_2)`

Given:
`p_(total)=97.1 kPa`

`p_(H_2O)=3.2kPa`

`p_(H_2)= ?kPa`

Thus
`97.1kPa=3.2kPa+p_(H_2)`

`p_(H_2)= 93.9kPa`