# Molality

The molality of a solution is defined as the number of moles of the solute per kilogram of solvent.

Molarity is usually denoted by the letter M, and molality is denoted by the letter m.

Example

Calculate the molarity of a solution that contains 18.65 g of KCl in 3 liters of solution.

Solution

We have 18.65 grams of KCl, and the total volume of the solution is 3 liters. First, find the number of moles of KCl present. The number of moles of KCl is 0.25 mol, which can be calculated from the formula weight and the grams of solute.