Basic Concept

Molality (m) of a solution is a ratio giving the number of moles of solute per kilogram of solvent.

  Molality (m) = moles of solute (n) / kilograms of solvent

This module is to calculate the molality of a solution by knowing the moles of the solute directly or indirectly, and the mass of the solvent; or calculate either the moles of the solute or the mass of the solvent by known the molality and the other quantity.

User Instructions

Calculate Molality:

Question: What is the molality of a solution prepared by dissolving 50.0 g of AgNO3 to 350.0 g of H2O?

This is one step process, enter the known data and press Calculate to output the unknowns.

1. Select Molality link from the front page or Molality tab from the Solution module. The Input and Output screen appears.

2. In the Input area, enter the three known quantities with a proper significant figure. Select the units associated with the input.

3. Click Calculate to output the answer.

4. The Show Work area on the right shows you step-by-step how your problem has been solved.

To start a new problem, click Reset. All Input fields will be cleared. Follow Step 1-3 again.