Molality Calculator

How to Use This Calculator

To use this molality calculator, enter the mass of the solute and select the appropriate unit, then do the same for the mass of the solvent. Click the "Calculate Molality" button. The result will be shown in mol/kg.

What This Calculator Is Used For

This calculator helps in determining the molality of a solution, which is defined as the number of moles of solute per kilogram of solvent. It is especially useful in chemistry when dealing with temperature-independent concentration units.

Formula

\[ \text{Molality (m)} = \frac{\text{moles of solute}}{\text{mass of solvent (kg)}} \]
\[ \text{Moles of solute} = \frac{\text{mass of solute (g)}}{\text{molar mass (g/mol)}} \]

Example

Suppose you dissolve 10 g of NaCl (molar mass = 58.44 g/mol) in 0.5 kg of water.
Moles of NaCl = 10 / 58.44 ≈ 0.171 mol
Molality = 0.171 / 0.5 = 0.342 mol/kg