Question

A flask contains 1/3 mole of h2 and 2/3 mol of he. Compare the force on the wall per impact of h2 relative to that for he.

Answer 1

1/2

Step-by-step explanation:

By Raoult's Law, the pressure of a gas in a gas mixture, is its mole fraction multiplied by the total pressure of the gas mixture. Thus, calling Pt as the total pressure:

`P_{H_(2)} = (1)/(3) *Pt`

`P_(He) = (2)/(3) *Pt`

The pressure is the force divided by the area, thus:

`\frac{F_{H_(2)}}{A} = (1)/(3) *Pt`

`(F_(He))/(A) = (2)/(3)*Pt`

Because the area is the same:

`\frac{F_{H_(2)}}{F_(He)} = (1/3)/(2/3)`

`\frac{F_{H_(2)}}{F_(He)} = (1)/(2)`

Answer 2

The force on the wall is actually the pressure exerted by gas molecules

Higher the pressure more the force exerted on the walls of container

The pressure depends upon the number of molecules of a gas

In a mixture of gas the pressure depends upon the mole fraction of the gas

As given the mole fraction of He is more than that of H2 therefore He will exert more pressure on the wall

The ratio of impact will be

H2 / He = 2/3 / 1/3 = 2: 1