What concentration of nitrogen should be present in a glass of water at room temperatrure ? Assume a temperature of `25^(@)C`, a total pressure of one atmosphere and mole fraction of nitrogen in air as 0.78 `(K_(H)` for nitrogen=8.42x`10^(-7) (M)/(mm Hg)`

Answer

`4.99xx10^(-4)M`

Explanation

`p_(N_(2))`= mole fraction of `N_(2)` in air `xx R_("total")=0.78 xx"1 atm = 0.78 atm = "0.78xx"760 mm= 592.8 mm"`
As Kis in the units of M `(mm)^(-1)`, Henry's law is applied in the form :
Conc. In solluiton `=K_(H)p_(N_(2))=8.42xx10^(-7)M(mm)^(-1)xx592.8mm = 4.99xx10^(-4)M`