In a flask of volume 'V' litres, 0.2 moles of O2, 0.4 moles of N2, 0.1 moles of NH3 and 0.3 moles of He gases are present at 27°C. If the total pressure exerted by these non-reacting gases is 1 atm, the partial pressure exerted by N2 gas is:

To find the partial pressure of N2 gas, we can use Dalton's Law of Partial Pressures, which states that the partial pressure of a gas is the ratio of its moles to the total moles multiplied by the total pressure. Total Moles: n_total = 0.2 moles O2 + 0.4 moles N2 + 0.1 moles NH3 + 0.3 moles He = 1.0 moles. Partial Pressure of N2 = (n_N2 / n_total) x P_total = (0.4/1.0) x 1 atm = 0.4 atm. Thus, the partial pressure exerted by N2 gas is 0.4 atm.