Question

Which of the following solutions exhibits highest freezing point depression?

Options

• 0.1 m NaCl

• 0.05 m MgSO₄

• 1 m AlPO₄

• 0.05 m Al₂(SO₄)₃

Answer 1

1 m AlPO₄

Explanation:

\[\mathrm{NaCl\longrightarrow Na^{+}+Cl^{-}}\] Total no. of particles = 0.1 + 0.1 = 0.2m

\[\mathrm{MgSO}_{4}\longrightarrow\mathrm{Mg}^{2+}+\mathrm{SO}_{4}^{2-}\] Total no. of particles = 0.05 + 0.05 = 0.1 m

\[\mathrm{AlPO}_4\longrightarrow\mathrm{Al}^{3+}+\mathrm{PO}_4^{3-}\] Total no. of particles = 1 + 1 = 2m

\[\mathrm{Al}_{2}(\mathrm{SO}_{4})_{3}\longrightarrow2\mathrm{Al}^{3+}+3\mathrm{SO}_{4}^{2-}\] Total no. of particles = 0.10 + 0.15 = 0.25 m

1m AIPO; solution has maximum no. of particles, hence it shows highest freezing point depression.