Molarity Calculator - Calculate Solution Concentration

Molarity Calculator

Calculate molarity, moles, volume, mass, solution dilution, mixing, and gas solubility with step-by-step solutions and detailed explanations.

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Molarity Calculator

Select calculation mode and enter values to calculate molarity, moles, volume, mass, dilution, mixing, or gas solubility

Calculation Mode

Moles (n) *

Number of moles of solute

Volume (V) *

Volume of solution

Key Concepts

Amount of Substance (n)

The amount of substance, measured in moles (mol), represents the number of particles (atoms, molecules, ions) in a sample. One mole contains $6.022 \times 10^{23}$ particles (Avogadro's constant).

Molarity (c)

Molarity is defined as the number of moles of solute per liter of solution: $c = \frac{n}{V}$ . It's the most common concentration unit in chemistry laboratories.

Molar Volume

At standard temperature and pressure (STP: 273.15 K, 101.325 kPa), one mole of any ideal gas occupies $22.4 \text{ L}$ . This is useful for converting between gas volumes and moles.

Practical Applications

Laboratory preparation: Calculate exact amounts needed to prepare solutions of specific concentrations.
Chemical reactions: Use molarity to determine stoichiometric relationships in reactions.
Quality control: Verify solution concentrations in manufacturing and pharmaceutical industries.
Dilution protocols: Prepare working solutions from stock solutions efficiently.

Important Notes

Always ensure units are consistent (convert mL to L when necessary).
Molarity depends on temperature - volume changes with temperature.
For gas solubility, actual results may differ if the gas reacts with water (e.g., HCl, NH₃).
When mixing solutions, ensure they contain the same solute to avoid precipitation.

How to Use This Calculator

Select a calculation mode, enter the required values, and click "Calculate" to get step-by-step solutions with detailed explanations.

Molarity: Calculate concentration from moles and volume using

c = \frac{n}{V}

Moles: Find the number of moles from molarity and volume using

n = c \times V

Volume: Determine the volume needed using

V = \frac{n}{c}

Mass: Convert between moles and mass using

m = n \times M

Dilution: Calculate using

C_1 V_1 = C_2 V_2

Mixing: Find final concentration using

C = \frac{C_1 V_1 + C_2 V_2}{V_1 + V_2}

Gas Solubility: Calculate molarity when gas dissolves in water.

Learn More About Molarity and Solutions

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Frequently Asked Questions

What is molarity?

Molarity (M) is moles of solute per liter of solution: M = n/V. A 1 M solution has 1 mole of solute in enough solvent to make 1 L of solution.

How do I calculate moles from mass?

moles = mass / molar mass. Example: 58.44 g of NaCl (molar mass 58.44 g/mol) = 1 mole.

What is the dilution formula?

M1V1 = M2V2, where M1 and V1 are the concentrated stock solution and M2 and V2 are the diluted solution. Rearrange to solve for the unknown.

What is the difference between molarity and molality?

Molarity (mol/L) uses solution volume and changes with temperature. Molality (mol/kg) uses mass of solvent and is temperature-independent — useful for colligative properties.

How do I prepare a solution of a specific molarity?

Compute required moles from M × V, convert to mass (mass = moles × molar mass), dissolve in a fraction of the final volume, then dilute to the final mark.

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