3.6 g of glucose (CHO, molar mass 180 g/mol) is dissolved in 200 g of water. The molal freezing point depression constant of water is 1.85 K kg/mol. By how many kelvin does the freezing point fall?

Answer and explanation

Correct answer: B. 0.185 K

  1. Step 1: Moles of solute mol.
  2. Step 2: Molality mol/kg, so K.
Answer
0.185 K.
Why not the others: 0.37 K: it treats the solute as dissociating into two particles. 0.019 K: the water mass is not converted from g to kg. 0.037 K: the amount is divided by the mass of the solute instead of the solvent.

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