Molarity Calculator

Prepare solutions with precision. Calculate Molarity, Mass required, or Dilution volumes.

Basic Molarity

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Ready to Calculate

Select a mode and enter values to find Molarity, Mass, or Dilution volumes.

Mastering Solution Preparation

Molarity is the standard for expressing concentration in the laboratory. Whether you are preparing a buffer, diluting an acid, or calculating reaction stoichiometry, accurate molarity calculations are fundamental to chemical precision.

Basic Formula

M = n / V

Moles per Liter

Mass Required

m = M × V × MW

For preparing solids

Dilution Law

M₁V₁ = M₂V₂

Conservation of Moles

Calculating Molarity

To find Molarity (M), you need two values:

  • Moles (n): The amount of solute. If given in grams, divide by Molar Mass.
  • Volume (V): The total volume of solution **in Liters**.

Preparation Example

Prepare 500 mL of 0.5 M NaCl.

  1. MW of NaCl = 58.44 g/mol
  2. Vol = 0.5 L, Molarity = 0.5 M
  3. Mass = 0.5 × 0.5 × 58.44
  4. Weigh 14.61 g of NaCl
  5. Dissolve in water up to 500 mL mark.

Explore More Chemistry Tools

Solution Dilution

Calculate M1V1 = M2V2.

Molality

Moles per kilogram.

Molar Mass

Grolar weight.

Frequently Asked Questions

What is Molarity (M)?

Molarity (M) is defined as the number of moles of solute dissolved per liter of solution. It is the most common unit of concentration in chemistry. Formula: M = n / V.

How do I calculate Molarity?

Divide the number of moles of solute by the total volume of the solution in liters. If you have grams, first convert to moles using the Molar Mass.

What is the Dilution Equation?

The dilution law is $M_1V_1 = M_2V_2$. It states that the moles of solute remain constant before and after dilution. You can use this to find how much stock solution is needed to reach a target concentration.

What is the difference between Molarity and Molality?

Molarity (M) depends on Volume (mol/L) and changes with temperature. Molality (m) depends on Mass of solvent (mol/kg) and is temperature-independent. Molarity is used for general lab work; Molality for colligative properties.

How do I prepare a 1 Molar NaCl solution?

Weigh out 58.44g of NaCl (1 mole). Dissolve it in a small amount of water, then add enough water to make the total volume exactly 1 Liter.

Can Molarity be higher than 1?

Yes, concentrated acids can be very high (e.g., Conc. H₂SO₄ is ≈18 M). However, there is a physical limit based on solubility.

Does temperature affect Molarity?

Yes. As temperature increases, liquids usually expand (Volume increases). Since M = n/V, the Molarity decreases slightly as temperature rises.

How to convert grams per liter (g/L) to Molarity?

Divide the concentration in g/L by the Molar Mass (g/mol) of the solute.

What is a 'Stock Solution'?

A concentrated solution stored for convenience. It is diluted with solvent to prepare solutions of lower concentration for experiments.

What is Normality (N)?

Normality is Molarity multiplied by the 'equivalence factor' (usually number of H⁺ or OH⁻ ions). For HCl, 1M = 1N. For H₂SO₄, 1M = 2N.