A mixture of hydrogen and oxygen at `1` bar pressure contains `20%` of hydrogen by weight. Calculate the partial pressure of hydrogen.

Explanation

`%` of `H_(2)=20, %` of `O_(2)=80`
`n_(H_(2))=20/2=10, n_(O_(2))=80/32=2.5`
`x_(H_(2))=10/(10+2.5)=10/12.5=0.8`
`p_(H_(2))=x_(H_(2))xxP_(H_(2))^(0)=0.8xx1 "bar"=0.8 "bar"`