Question

A 5.2 molal aqueous solution of methyl alcohol, `CH_(3)OH`. What is the mole fraction of methyl alcohol in solution?
A. `0.190`
B. `0.080`
C. `0.050`
D. `0.100`

Answer 1

Correct Answer - D
Moles of `CH_(3)OH = 5.2`
Mass of `CH_(3)OH=5.2xx32=166.4g`
Mass of water `=1000-166.4=833.6`
Moles of water `= (833.6)/(18)=46.3`
Mole fraction of `CH_(3)OH=(5.2)/(46.3+5.2)`
`=(5.2)/(51.5)=0.1`.