Q.
The vapour pressure of water at 80∘C is 355.5 mm Hg.A100mL vessel contains water saturated with O2 at 80∘C, the total pressure being 760 mm of Hg. The contents of the vessel were pumped into a 50mL vessel at the same temperature. What is the partial pressure of O2?
pTotal=pH2O+pO2pH2O=760−355.5=404.5mmHg
When the contents were pumped into 50mL vessel p1−404.5mmHg, V1=100mL,p2=?V2=50mL P1V1=P2V2 p2=50404.5×100=809
Thus, pO2 in 50mL vessel = 809mmHg