Question

The freezing point (in `.^(@)C)` of a solution containing `0.1 g` of `K_(3)[Fe(CN)_(6)]` (Mol.wt. 329) in 100 g of water `(K_(f) = 1.86 K kg mol^(-1))` is
A. `-2.3 xx 10^(-2)`
B. `-5.7 xx 10^(-2)`
C. `-5.7 xx 10^(-3)`
D. `-1.2 xx 10^(-2)`

Answer 1

Correct Answer - A
`DeltaT_(f) = m xx K_(f) xx i`
`=(0.1//329)/(100) xx 1000 xx 1.86 xx 4 = 0.2261`
`= 2.3 xx 10^(-2)`
`T_(f) = 0 - DeltaT_(f) =- 2.3 xx 10^(2).^(@)C`