In a 1 L flask, 250 mL nitrogen at 720mm pressure and 380 mL of oxygen at 650 mm pressure are taken together. If temperature is kept constant, what will be the pressure of the mixture?

Explanation

Nitrogen : `V_(1)= 250 mL, P_(1)= 720mm, v_(2)= 1000 mL`, then
Partial pressrue of oxygen, `P_(N_2)= (720 mm xx 250 mL)/(1000 mL)= 180mm`
Oxygen : `V_(1)= 380 mL, P_(1)= 650 mm, V_(2)= 1000 mL`, then
Partial pressure of oxygen, `P_(O_2) = (650 mm xx 380 mL)/(1000 mL)= 247 mm`
By Dalton.s law of partial pressures, total pressure, `P= P_(N_2)+P_(O_2)= 180+247= 427 mm`.