Assuming that dry air.contains 79% `N_(2)` and 21% `O_(2)` by volume, calculate the density of moist air at `25^(@)C` at one atmosphere when the relative humidity is 60%. The vapor pressure of water at `25^(@) `C is 23.76 mm of Hg.

Options

A. `1.17 g L^(-1)`
B. `2.16 g L^(-1)`
C. `3.12 g L^(-1)`
D. `4.16 g L^(-1)`

Answer

A

Explanation

`P_("Total") = 760 mm , P_(H_(2) O) = 23.76 (06) = 14.25` mm
`P_(N_(2)) = (745.744) (0.79) = 583.13 mm , P_(O_(2)) = (745.744)(0.21) = 156.6` mm
`MW_("mix") = ((18) (14.256) + (589.1) 28 + (156.6 )32)/(760) = 28.63 implies d = (PM)/(RT) = 1.17`