"Dalton's law of partial pressures"Dalton's law of partial pressures, which was established by experiment, holds that in a gaseous mixture, the pressure exerted by an individual component gas is the same as the pressure it would exert if it alone occupied the container.
And so, P_"Total"=P_A+P_B+P_C........., where A, B, C, etc are the individual, component gases.
But if we assume ideality, P_A=(n_ART)/V, where n_A is the number of moles of "component gas A".
And so, P_"Total"=(n_ART)/V+(n_BRT)/V+(n_CRT)/V.........,
Equivalently, P_"Total"=(RT)/V{n_A+n_B+n_C.....}.
And thus the partial pressure, P_A, is proportional to the mole fraction:
P_A=(RT)/Vxxn_A/(n_A+n_B+n_C.....), the constant of proportionality is of course (RT)/V
