Question

Which of the following salt will have same value of van't Hoff’s factor as that of K₄ [Fe (CN)₆ ]?

(a) Al₂ (SO₄)₃ 

(b) NaCl 

(c) Al(NO₃)₃ 

(d) Na₂SO₄

Answer 1

Correct option  (a) Al₂(SO₄)₃

Explanation:

 K₄ [Fe(CN)₆] dissociates as 4K+ & [Fe(CN)₆]^4–. Thus 1 molecule dissociates into five particles. In the same way Al₂ (SO₄)₃ also dissociates as  Al₂ (SO₄)₃  → 2Al₃+ + 3SO₄^2–