Hydrogen is collected over water at 0.975 atm and 28°C. What is the partial pressure of H_2?

Apr 24, 2018

Well, we need the $\text{saturated vapour pressure}$, ${P}_{\text{SVP}}$, of water at $301.15 \cdot K$

Explanation:

${P}_{\text{measured"=P_"dihydrogen"+P_"SVP}}$

${P}_{\text{dihydrogen"=P_"measured"-P_"SVP}}$

This site gives ${P}_{\text{SVP}} = 28 \cdot m m \cdot H g$ at $25$ ""^@C. These data SHOULD have been supplied with the question.

And so..............................

${P}_{\text{dihydrogen}} = 0.975 \cdot a t m - \frac{28 \cdot m m \cdot H g}{760 \cdot m m \cdot H g \cdot a t {m}^{-} 1} = 0.938 \cdot a t m$