Understanding Molality

Molality (m) is a measure of concentration defined as the number of moles of solute per kilogram of solvent.

Steps to Calculate Molality

1. Calculate the moles of NaCl:

- You'll need the molar mass of NaCl (sodium chloride). It's approximately 58.44 g/mol.

- Convert the mass of NaCl (0.2 kg) to grams: 0.2 kg * 1000 g/kg = 200 g

- Divide the mass of NaCl by its molar mass to get moles: 200 g / 58.44 g/mol ≈ 3.42 mol

2. Convert the mass of water to kilograms:

- You have 3 kg of water.

3. Calculate Molality:

- Divide the moles of NaCl by the kilograms of water: 3.42 mol / 3 kg ≈ 1.14 mol/kg

Therefore, the molality of the solution is approximately 1.14 mol/kg.