Answer:
0.91 atm is the partial pressure of just hydrogen gas.
Step-by-step explanation:
Vapor pressure of water , p= 0.0313 atm
Partial pressure of hydrogen gas =
![p_(H_2)](https://img.qammunity.org/2021/formulas/chemistry/high-school/wye0xq2062j2b23e79qtywrbqtmna70rd8.png)
Total pressure of the water vapors and hydrogen gas = P = 715 Torr
1 atm = 715 Torr
![715 Torr=(715)/(760) atm=0.94 atm](https://img.qammunity.org/2021/formulas/chemistry/high-school/85uadoqanuqbo21laduos59dnak2p41cln.png)
According Dalton's law of partial pressure:
![P=p+p_(H_2)](https://img.qammunity.org/2021/formulas/chemistry/high-school/3i6svdbtb71y6vsg62urf3u2mzfik5mhbj.png)
![0.94 atm=0.0313 atm+p_(H_2)](https://img.qammunity.org/2021/formulas/chemistry/high-school/ev0xz7mcw87wua8jfcncwigxgp1y2w3yii.png)
![p_(H_2)=0.94 atm - 0.0313 atm =0.9087 atm \approx 0.91 atm](https://img.qammunity.org/2021/formulas/chemistry/high-school/bs60mgzmt0omaa9ftxk9hrg8c21ost3o2y.png)
0.91 atm is the partial pressure of just hydrogen gas.