Answer the following in one or two sentences. Which of the following solution will have higher freezing point depression and why? i. 0.1 m NaCl ii. 0.05 m Al2(SO4)3 - Chemistry

Exercise | Q 2.07 | Page 45

Answer the following in one or two sentences.

Which of the following solution will have higher freezing point depression and why?

i. 0.1 m NaCl

ii. 0.05 m Al2(SO4)3

Solution:

For 0.1 m NaCl:

NaCl   →   Na⁺     +    Cl^-

0.1 m       0.1 m         0.1 m 

Total particles in solution = 0.2 mol

For 0.05 m Al₂(SO₄)₃:

Al₂(SO₄)₃    →  2Al³⁺     + 3${\displaystyle {\text{SO}}_4^{2-}}$

0.05 m             0.1 m            0.15 m

Total particles in solution = 0.25 mol

Al₂(SO₄)₃ solution contains more number of particles than NaCl solution. Hence, Al₂(SO₄)₃ solution has maximum ΔT_f.

Therefore, the freezing point depression of 0.05 m Al₂(SO₄)₃ solution will be higher than 0.1 m NaCl solution.