Correct Answer - d
(d) % Relative humidity
`=("Partial pressure of "H_(2)O)/("Vapour pressure of " H_(2)O)xx100`
`75=(P_(H_(2)O))/(30)xx100`
`P_(H_(2)O)=22.5"torr,"`
% of `H_(2)O` vapour in air
`=((22.5))/(760)xx100=2.96`
molar mass of wet air
`=(29xx97.04+2.96xx18)/(100)`
`=(2814.16+53.28)/(100)=28.67`
density of wet air `=(PM)/(RT)=(1xx28.67)/(0.0821xx300)`
`=1.164g//L`