Molality (m) measures concentration as moles of solute per kilogram of solvent. It is temperature-independent.

When should I use molality instead of molarity?

Use molality for colligative property calculations and when working at varying temperatures.

How do I convert molality to molarity?

You need the density of the solution. M = m × d / (1 + m × Mw/1000), where d is density and Mw is molar mass of solute.

Free Molality Calculator

Calculate the molality of a solution from moles of solute and mass of solvent in kilograms.

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Moles of Solute

mol

Mass of Solvent

Molality

0.5000 m

Molality vs Moles of Solute

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How to Calculate Molality

Formula

m = n / w

Where:

m = molality (mol/kg)

n = moles of solute

w = mass of solvent in kilograms

Molality does not change with temperature because mass is temperature-independent.

Example Calculation

Dissolve 0.5 moles of glucose in 1 kg of water.

01m = n / w
02m = 0.5 mol / 1 kg
03m = 0.5 mol/kg

Frequently Asked Questions

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Understanding Molarity

Learn what molarity is, how to calculate it, and why it matters in chemistry. Covers moles, liters, dilution, and step-by-step examples for preparing solutions.

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