Question

if the partial pressures are oxygen 420 torr and helium 85 torr what is the partial pressure (torr) of the nitrogen in the mixture

Answer 1

Dalton’s Law of Partial Pressure states the total pressure exerted by a mixture of gases is equal to the sum of the partial pressure of each individual gas.

Thus;

P_TOTAL = P_O2 + P_H2 + P_N2

925 torr = 420 torr + 85 torr. + P_N2

P_N2 = 925 torr - 505 torr = 420 torr.