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Rama09 [41]
4 years ago
6

the freezing point of a solution made by dissolving 12.4 g nonelectrolyte in 100.0 g water is -5.00celcuis. calculate the molar

mass of the electrolyte​
Chemistry
1 answer:
GalinKa [24]4 years ago
5 0

Answer:

46.13 g/mol.

Explanation:

∵ ΔTf = Kf.m.

Where,  ΔTf is the depression in the freezing point of water = 5.0°C.

Kf is the the molal freezing point depression constant of water = 1.86 °C/m.

m is the molality of the solution (moles of solute per kilogram of solvent.)

∵ ΔTf = Kf.m.

<em>∴ m = ΔTf /Kf</em> = (5.0°C)/(1.86 °C/m) = <em>2.688 m.</em>

∵ m = no. of moles of solute / kg of solvent.

∴ 2.688 m = (mass of solute / molar mass of solute) / kg of water.

<em>∴ Molar mass of solute = (mass of solute)/(2.688)(kg of water)</em> = (12.4 g)/(2.688)(0.10 kg) = <em>46.13 g/mol.</em>

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