A mixture has 18 g water and 414 g ethanol . The mole fraction of water in mixture is (assume ideal behaviour of the mixture )______.

Options

A. `0.1`
B. `0.4`
C. `0.7`
D. `0.9`

Answer

A

Explanation

Mole fraction
`=("Number of moles of water")/("Number of moles of water+ number of moles of ethanol")`
`=(w//m)/(w/m+W/M)`
`Mol.wt.ofH_(2)O=18,mol.wt.ofC_(2)H_(5)OH=46`
`"Mole fraction of water"=(18//18)/(18//18+414//46)=0.1`