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))_(3)rArr2Al^(3+)+3SO_(4)^(2-)`
Value of van't Hoff's factor (i) = 5
`{:((a),K_(2)SO_(4)hArr 2K^(+)+SO_(4)^(2-),(i=3)),((b),K_(3)[Fe(CN)_(6)]hArr3K^(+)+[Fe(CN)_(6)]^(3-),(i=4)),((c ),Al(NO_(3))_(3)hArr Al^(3+)+3NO_(3)^(-),(i=4)),((d),K_(4)[Fe(CN)_(6)]hArr 4K^(+)+[Fe(CN)_(6)]^(3-),(i=5)):}`
Therefore, `K_(4)[Fe(CN)_(6)]` has same value of i that of `Al_(2)(SO_(4))_(3)` i.e. i = 5.