What is mole fraction of methyl alochol in a 5.2 molal aqueous solution of methyl alcohol, `CH_(3)OH`.

Options

A. 0.1
B. 0.19
C. 0.086
D. 0.05

Answer

C

Explanation

5.2 molal methanol.
`:.` 5.2 mole of methanol in 1000 g water.
Mole of water `= (1000)/(18) = 55.56`
Total mole `= 5.2 + 55.56 = 60.76`
Mole fraction of methanol `=("mole of methanol")/("total mole")`
`= (5.2)/(60.76) = 0.08558 ~~0.086`