Question

A solution is made by dissolving9.68 g of potassium chloride(KCI) in 565 g of water.What is the molality of the solution?[?] m KCIMolar mass of KCI: 74.55 g/mol

Answer 1

Molality = 0.230 m KCl

Step-by-step explanation

Given

Mass of solute (potassium chloride) = 9.68 g

Mass of water (solvent) = 565 g = 0.565 kg

Molar mass of KCl = 74.55 g/mol

Required: Molality of the solution

Solution

Step 1: Calculate the moles of the solute

n = m/M where n is the moles, m is the mass and M is the molar mass

n = 9.68g/74.55g/mol

n = 0.130 moles

Step 2: Calculate the molality (Make sure the mass of solvent is in kg)

Molality = moles of the solute/Kg of solvent

Molality = 0.130 mol/0.565kg

Molality = 0.230 mol/kg (or 0.230 m)