A solution of sucrose (molar mass `= 342 g mol^(-1))` has been prepared by dissolving 68.5g of sucrose in 1000g of water. The freezing point of the solution obtained will be: `(K_(f)` for water `= 1.86 K kg mol^(-1))`

Options

A. `+0.372^(@)C`
B. `-0.570^(@)C`
C. `-0.372^(@)C`
D. `-0.520^(@)C`

Answer

C

Explanation

`Delta T_(f) = K_(f) m`
Molaltiy , ` m = (6.86//342)/(100) xx 1000 = 0.2`
`therefore Delta T_(f) = 1.86 xx 0.2 = 0.372`
`therefore` Freezing point of solution `= 0-0.372`
` = 0- 372^(@)C`