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 ` = (16g " of"O_(2))/(32g"mol"^(-1)) + (7g "of" N_(2))/(28 g"mol"^(-1)) + (1g "of" H_(2))/(2g "mol"^(-1))`
Total number of moles ` = (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 ` = P_(O_(2)) = ("number moles of " O_(2))/("total number of moles") xx "pressure" = (1)/(2) xx (4)/(7) xx 21 = 6` atm
Similarly, `P_(N_(2)) = (1)/(4) xx (4)/(7) xx 21 = 3` atm
Similarly, `P_(H_(2)) = (1)/(1) xx (4)/(7) xx 21 = 12` atm