What is the freezing point depression constant (K_f) of water when 1.00 mol of a non-volatile non-electrolyte dissolved in 1.00 kg of water depresses the freezing point by 1.86 °C?
Answer and explanation
Correct answer: A. 1.86 °C kg / mol
- Step 1: Freezing point depression formula: delta T_f = K_f m. Step 2. Here delta T_f = 1.86 °C and m = 1.00 mol / 1.00 kg = 1.00 m. Step 3. K_f = delta T_f / m = 1.86 °C / 1.00 m = 1.86 °C kg / mol. Answer: 1.86 °C kg / mol. Why not the others:* 0.512 °C kg/mol is the boiling point elevation constant (K_b) of water.
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