Match the following aqueous solutions with the appropriate letter from the column on the right. 1. 0.24 m KCH3COO A. Lowest freezing point 2. 0.11 m Al(NO3)3 B. Second lowest freezing point 3. 0.13 m Cr(NO3)2 C. Third lowest freezing point 4. 0.41 m Ethylene glycol(nonelectrolyte) D. Highest freezing point

1 ⇒ A

2 ⇒ B

3 ⇒ D

4 ⇒  C

Explanation:

We use the Freezing point depression to solve this:

Freezing T° pure solvent - Freezing T° of solution = Kf . m . i

1. Potassium acetate:

0°C - Freezing T° of solution = 1.86°C/m . 0.24m . 2

KCH₃COO → K⁺ + CH₃COO⁻   i = 2

Freezing T° of solution = -1.49°C (A)

2. Aluminum nitrate:

0°C - Freezing T° of solution = 1.86°C/m . 0.11m . 4

Al(NO₃)₃ → Al³⁺ + 3NO₃⁻    i= 4

Freezing T° of solution = -0.82°C (B)

3. Chromium (II) nitrate

0°C - Freezing T° of solution = 1.86°C/m . 0.13m . 3

Cr(NO₃)₂ → Cr²⁺ + 2NO₃⁻    i= 3

Freezing T° of solution = - 0.72°C (D)

4. Ethylene glycol(nonelectrolyte) → I = 1

0°C - Freezing T° of solution = 1.86°C/m . 0.41m . 1

Freezing T° of solution = - 0.76°C  (C)