Question

How can you calculate partial pressure?

Answer 1

By means of `"Dalton's Law of Partial Pressures"`.

Explanation:

In a gaseous mixture, the pressure exerted by a component, `P_A`, is the same as the pressure it would exert if it ALONE occupied the container. The total pressure is the sum of the individual partial pressures.

`P_"Total"` `=` `P_A + P_B + P_C + P_D........`

And if we assume ideality,

`=` `(n_ART)/V+(n_BRT)/V+(n_CRT)/V+(n_DRT)/V+`

Thus, `P_"Total"` `=` `(RT)/V{n_A + n_B + n_C + n_D + }`

And `P_A` `=` `(RT)/Vxxn_A/{n_A + n_B + n_C + n_D + }`

Thus the partial pressure `P_Aprop"Mole fraction of Gas A"`, with the constant of proportionality `(RT)/V`.