A solution is prepared by dissolving 2.61 g ethanol (C2H5OH) in 16.2 g water. What is the molality (mol/kg) of C2H5OH in the solution?

3.50 molal

Explanation:

Molality → Moles of solute / kg of solvent.

Let's convert the solvent's mass from g to kg

16.2 g. 1kg / 1000 g = 0.0162 kg

Let's determine the moles from the solute

2.61 g. 1 mol / 46 g = 0.0567 moles

Molality → 0.0567 mol / 0.0162 kg = 3.50 m