138 g of ethyl alcohol is mixed with 72 g of water. The ratio of mole fraction of alcohol to water is

Options

A. `3 : 4`
B. `1 : 2 `
C. `1 : 4`
D. `1 : 4`

Answer

A

Explanation

`x_("ethylalc") = n_(1)/(n_(1) + n_(2))= ((130//46))/((138//46)+(72//18))=3/(3+4) = 3/7`
`x_(H_(2)O)=n_(2)/(n_(1) + n_(2))=(72//18)/((138//46) + (72//18))=4/(3+4) = 4/7`
`x_("ethyl alconol")/x_(H_(2)O)=(3//7)/(4//7)=3/4`