To answer the given problem, assume that the given gases: oxygen, hydrogen, and nitrogen behave as ideal gases. The assumption is relevant so that we can make use of the partial pressure additivity of ideal gases. To determine the partial pressure exerted by nitrogen, subtract the partial pressures exerted by oxygen and hydrogen from the total pressure.
P (nitrogen) = P (total) - P (oxygen) - P (hydrogen)
P (nitrogen) = 378 kPa - 212 kPa - 101 kPa = 65 kPa
Thus, the partial pressure exerted by nitrogen is 65 kPa.
