A two litre flask contains a mixture of 16g of oxygen, 7g of nitrogen and 2g of hydrogen at `20^@C`. Report the total pressure and partial pressures.

Explanation

Total number of moles of mixture = `(16 g " of " O_2)/(32 g mol^(-1)) + (7g " of " N_2)/(28 g mol^(-1)) + (2g " of " H_2)/(2g mol^(-1)) = 1/2 + 1/4 + 1 = 7/4`
Using ideal gas equation,
` P = n (RT)/V = 7/4 xx (0.0821 xx 293)/(2) = 21 atm`
Partial pressure of oxygen =
`("number of moles of" O_2)/("total number of moles ") xx "pressure" = 1/2 xx 4/7 xx 21 = 6 atm`
Partial pressure of nitrogen=`1/4 xx 4/7 xx 21 = 3 atm`
Partial pressure of hydrogen = `1/2 xx 4/7 xx 21 = 12 atm`.