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

Explanation

As the mixture of `H_(2)` and `O_(2)` contains 20% by weight of dihydrogen, therefore, if `H_(2)`=20 g, then `O_(2)`=80 g
`n_(H_(2))=(20)/(2)=10" moles", n_(O_(2))=(80)/(32)=2.5" moles"`
`p_(H_(2))=(n_(H_(2)))/(n_(H_(2))+n_(O_(2)))xxP_("total")=(10)/(10+2.5)xx1" bar"=0.8" bar"`