A `5.2` molal aqueous of methyl alcohol, `CH_(3)OH`, is supplied. What is the molefraction of methyl alcohol in the solution ?

Options

A. `0.190`
B. `0.086`
C. `0.050`
D. `0.100`

Answer

B

Explanation

5.2 molal solution means 5.2 moles of the solute `(CH_(3) OH)` are present in 1000g of water i.e. 1000/18 moles = 55.55 moles of water.
`:. "Mole freaction of " CH_(3)OH=5.2/(5.2 + 55.55)=0.086`