When `20g` of naphtholic acid `(C_(11)H_(8)O_(2))` is dissolved in `50g` of benzene `(K_(f) = 1.72 K kg mol^(-1))` a freezing point depression of `2K` is observed. The van'f Hoff factor (i) is

Options

A. `0.5`
B. 1
C. 2
D. 3

Answer

A

Explanation

`DeltaT_(f) = iK_(f) (n)/(W//1000)`
`2 = ixx 1.72 xx (20//172)/(50//1000)`
`i= 0.5`