A solution of `x` moles of sucrose in `100`grams of water freeze at `-0.2^(@)C` As. Ice separates the freezing point goes down to `0.25^(@)C`. How many grams of ice would have separated ?

Options

A. 18 grams
B. 20 grams
C. 25 grams
D. 23 grams

Answer

B

Explanation

(i) `DeltaT_(f)=mxxK_(f)`
`0.2=(Xxx1000)/(100)xx1.86 X=(0.2)/(10xx1.86)`
after freezing
`DeltaT_(f)=(Xxx1000)/((100-y))xx1.86 DeltaT_(f)=0.25`
On solving, Amount of ice `y=20 g` ice