Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Physical: Solutions

Question:

Ethylene glycol is used as an antifreeze in a cold climate. What is the mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at -6oC? (Kf for water = 1.86 K kg/mol and molar mass of ethylene glycol = 62 g/mol)

Options:

400 g

304.60 g

800.00 g

204.30 g

Correct Answer:

800.00 g

Explanation:

Depression in freezing point, ΔTf = \(\frac{Kf × 1000 × W_2}{W_1 × M_2}\)

6 = \(\frac{1.86 × 1000 × W_2}{4000 × 62}\)

W2 = \(\frac{6 × 4000 × 62}{1.86 × 1000}\) = 800 g