Molarity Calculator

Calculate solution concentration and perform dilution calculations

Enter the required values to calculate the molarity (concentration) of your solution or to perform dilution calculations.

Examples

See how to use the Molarity Calculator in real scenarios.

Calculate Molarity from Moles and Volume

Molarity

Find the molarity of a solution containing 0.5 mol NaCl in 1.5 L solution.

Solute Amount (mol): 0.5 mol

Solution Volume: 1.5 L

Calculation Type: Molarity (mol/L)

Volume Unit: L (Liters)

Prepare Solution from Mass and Molar Mass

Prepare Solution

Prepare 250 mL of 0.2 M KCl solution. (Molar mass = 74.55 g/mol)

Solution Volume: 250 mL

Solute Mass (g): 3.73 g

Molar Mass (g/mol): 74.55 g/mol

Calculation Type: Prepare Solution (from mass)

Volume Unit: mL (Milliliters)

Dilute a Stock Solution

Dilution

Dilute 2.0 M HCl to make 500 mL of 0.5 M solution. How much stock do you need?

Initial Molarity (M1): 2 mol/L

Final Molarity (M2): 0.5 mol/L

Final Volume (V2): 500 L

Calculation Type: Dilution (M1V1 = M2V2)

Volume Unit: mL (Milliliters)

Find Molarity from Mass and Volume

Prepare Solution

What is the molarity if 10 g NaOH (molar mass 40.00 g/mol) is dissolved in 500 mL?

Solution Volume: 500 mL

Solute Mass (g): 10 g

Molar Mass (g/mol): 40 g/mol

Calculation Type: Prepare Solution (from mass)

Volume Unit: mL (Milliliters)

Other Titles
Understanding Molarity Calculator: A Comprehensive Guide
Master solution concentration, preparation, and dilution with step-by-step explanations and examples.

What is Molarity?

  • Definition of Molarity
  • Importance in Chemistry
  • Units and Notation
Molarity is a measure of the concentration of a solute in a solution, expressed as the number of moles of solute per liter of solution (mol/L). It is a fundamental concept in chemistry, used to describe how much of a substance is present in a given volume of solution.
Molarity Formula
The formula for molarity (M) is: M = n / V, where n is the amount of solute in moles and V is the volume of the solution in liters.

Molarity Examples

  • A solution with 1 mol NaCl in 1 L has a molarity of 1 M.
  • If 0.5 mol KCl is dissolved in 2 L, the molarity is 0.25 M.

Step-by-Step Guide to Using the Molarity Calculator

  • Choosing the Calculation Type
  • Entering the Correct Values
  • Interpreting Results
Select the calculation type: molarity, prepare solution, or dilution. Enter the required values such as moles, mass, molar mass, and volume. The calculator will instantly provide the result with detailed steps.
User-Friendly Interface
The calculator is designed for ease of use, with tooltips and validation to guide you through each step.

How to Use the Calculator

  • Calculate the molarity of a solution by entering moles and volume.
  • Find out how much solute is needed to prepare a specific molarity.

Real-World Applications of Molarity

  • Laboratory Solution Preparation
  • Industrial Chemistry
  • Education and Research
Molarity calculations are essential in laboratories for preparing solutions, in industry for quality control, and in education for teaching chemical concepts.
Versatile Uses
From pharmaceuticals to food science, molarity is a key parameter in many fields.

Applications

  • Preparing a buffer solution for a biology experiment.
  • Diluting a concentrated acid for safe laboratory use.

Common Misconceptions and Correct Methods

  • Volume vs. Solvent Volume
  • Mixing Units
  • Dilution Pitfalls
A common mistake is confusing the volume of solvent with the total solution volume. Always use the final solution volume in calculations. Ensure all units are consistent, and be careful with dilution formulas.
Best Practices
Double-check units and use the calculator's validation to avoid errors.

Misconceptions

  • Do not use only the solvent volume; always use total solution volume.
  • Convert mL to L when necessary.

Mathematical Derivation and Examples

  • Molarity Formula Derivation
  • Dilution Equation (M1V1 = M2V2)
  • Worked Examples
The molarity formula is derived from the definition of concentration. For dilutions, the equation M1V1 = M2V2 allows calculation of required volumes or concentrations.
Example Calculations
If you have 0.1 mol of solute in 250 mL (0.25 L), the molarity is 0.4 M. For dilution, to make 100 mL of 0.1 M from 1 M stock, use V1 = (M2 × V2) / M1 = (0.1 × 100) / 1 = 10 mL.

Derivation & Examples

  • Calculate molarity from mass, molar mass, and volume.
  • Use the dilution formula to prepare a desired concentration.