The amount of ice that will separate out on cooling a solution containing 50 g ethylene glycol in 200 g water to `-9.3^(@)C` is : (`K'_(f) = 1.86 K "molality"^(-1)`)

Options

A. 18.71 g
B. 28.71 g
C. 38.71 g
D. 48.71 g

Answer

C

Explanation

We have to calculate mass of liquid water that is present in the solution. The remaining will freeze as ice.
`DeltaT_(f)=(1000K_(f)w_(2))/(w_(1)M_(2))`
`9.3=(1000xx1.86xx50)/(w_(1)xx62)[M_(2)" for "{:(CH_(2)OH),(|),(CH_(2)OH):}=62]`
`or w_(1)=161.29g`
`therefore" Ice separated out "=200-161.29=38.71g`