To an evacuated vessel with movable piston under external pressure of 1 atm 0.1 mole of He and 1.0 mole of an unknown compound vapour pressure 0.68 atm at `0^(@)C` are introduced Considering the ideal gas behaviour the total volume (in litre) of the gases at `0^(@)C` is close to .

Answer

7

Explanation

For any ideal gas `PV =nRT`
For `He, n = 0.1 P =0.32` atm `V =? T =273`
`0.32 xx V =0.1 xx 0.0821 xx 273`
`V =7litre`
(unknown compound will not follow ideal gas equation) .