Question

A gaseous mixture of helium and neon at `1*atm` contains a partial pressure of `0.60*atm` with respect to helium. What is `P_"Ne"`?

Answer 1

`P_"Ne"=P_"Total"-P_"He"=0.40*atm........`

Explanation:

Dalton's law of partial pressures holds that in the gaseous mixture, the partial pressure exerted by a component is the same as the pressure as it would exert if it ALONE occupied the container. The total pressure is the sum of the individual partial pressures.

And thus `P_"Total"=P_"He"+P_"Ne"`. We are given `P_"Total"` and `P_"He"`; it is thus fairly straightforward to get `P_"Ne"` by difference.

For a more general treatment, see here.

Capisce?