# A sample of nitrogen gas was collected via water displacement. Therefore, the sample is saturated with water vapor. If the total pressure of the mixture at 21 °C is 1.50 atm, what is the partial pressure of nitrogen?

## The vapor pressure of water at 21°C is 18.7 mmHg

${P}_{\text{Total"=P_(N_2)+P_"SVP}}$.............${P}_{{N}_{2}} = 1.475 \cdot a t m$
Where ${P}_{\text{SVP"="saturated vapour pressure.....}}$, which here $= \frac{18.7 \cdot m m \cdot H g}{760 \cdot m m \cdot H g \cdot a t {m}^{-} 1} = 0.025 \cdot a t m$.
Thus ${P}_{{N}_{2}} = {P}_{\text{Total"-P_"SVP}} = \left(1.50 - 0.025\right) \cdot a t m = 1.475 \cdot a t m$