# What is the partial pressure of the helium gas? Express your answer in millimeters of mercury.

Jul 7, 2017

${P}_{\text{He}} = 203$ $\text{mm Hg}$

#### Explanation:

According to Dalton's law of partial pressures, the total pressure of the gaseous mixture is equal to the sum of the partial pressures of the gaseous components.

Therefore,

${P}_{\text{total" = P_ ("CO"_2) + P_ "Ar" + P_ ("O"_2) + P_ "He}}$

$745$ $\text{mm Hg}$ $= 133$ $\text{mm Hg}$ $+ 214$ $\text{mm Hg}$ $+ 195$ $\text{mm Hg}$ $+ {P}_{\text{He}}$

P_ "He" = color(red)(203 color(red)("mm Hg"