(i) For which property of the liquid the shape of a liquid drop is spherical?
(ii) In a 10 volumetric flask contains 1 g He and 6.4 g of `O_(2)` at `27^(@)C` temperature. If the total pressure of the mixture is 1.107 atm, then what is the partial pressure of He and `O_(2)`?

Explanation

(i) Surface tension.
(ii) `n_(He)=(1)/(4)=0.25 mol, n_(O_(2))=(6.4)/(32)=0.2` mol
`therefore`Total number of moles=(0.25+0.2)=0.45
`x_(He)=(0.25)/(0.45)=0.5555 and x_(O_(2))=(0.2)/(0.45)=0.4444`
`p_(He)=0.5555xx1.107atm=0.615`
`p_(O_(2))=0.4444xx1.0107atm=0.491atm`