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+     + 3SO42-

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 ΔTf.

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