A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. Calculate the partial pressure of dihydrogen.

Explanation

`"Mass of "H_(2)=20g`,
`"Moles of "H_(2)=(20)/(2)="10 mol,"`
`"Moles of "O_(2)=(80)/(32)="2.5 mol"`
`"Mole fraction of "H_(2)=(10)/(10+2.5)=0.8`
`"Partial pressure"=0.8xxp=0.8xx"1 bar"="0.8 bar"`