Which of the following electrolytes has the same value of van't Hoff factor (i)is that of `Al_(2)(SO_(4))_(3)`(if all are `100%`ionised)?

Options

A. `K_(2)SO_(4)`
B. `K_(3)[Fe(CN)_(6)]`
C. `Al(NO_(3))_(3)`
D. `K_(4)[Fe(CN)_(6)]`

Answer

D

Explanation

`Al_(2)(SO_(4))hArr2Al^(3+)+3SO_(4)^(2-)`
Value of van't Hoff's factor (i) = 5
(a) `K_(2)SO_(4)hArr2K^(+)+SO_(4)^(2-)(i=3)`
(b) `K_(3)[Fe(CN)_(6)]hArr3K^(+)+[Fe(CN)_(6)]^(3-)" "(i=4)`
(c) `Al(NO_(3))_(3)hArrAl^(3+)+3NO_(3)^(-)" "(i=4)`
(d) `K_(4)[Fe(CN)_(6)]hArr4K^(+)+[Fe(CN)_(6)]^(3-)" "(i=5)`
Therefore, `K_(4)[Fe(CN)_(6)]" has same value of i as that of "Al_(2)(SO_(4))_(3)i.e.i=5`.