Molarity & Concentration Converter

Calculate molarity, mass, volume, and moles for chemical solutions

g/mol

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What is Molarity?

Molarity (M) is a measure of the concentration of a solution, defined as the number of moles of solute per liter of solution. It's one of the most commonly used units in chemistry for expressing solution concentration. The formula for molarity is:

M = n / V

where M = molarity (mol/L), n = moles of solute, V = volume of solution (L)

Understanding molarity is essential for preparing solutions in chemistry labs, pharmaceutical research, biological experiments, and industrial applications. Our calculator helps you quickly convert between mass, molar mass, volume, molarity, and moles.

Common Applications

Solution Preparation

Calculate the exact amount of solute needed to prepare solutions of specific concentrations for experiments and analyses.

Dilution Calculations

Determine volumes and concentrations when diluting stock solutions for experiments or quality control.

Quality Assurance

Verify concentration accuracy in pharmaceutical, food, and chemical manufacturing processes.

Educational Purposes

Learn and practice stoichiometry, solution chemistry, and analytical chemistry concepts.

Understanding the Formulas

Calculating Molarity

To find molarity, first calculate moles from mass and molar mass:

n (moles) = mass (g) / molar mass (g/mol)

Then divide moles by volume in liters:

M (molarity) = n (mol) / V (L)

Calculating Required Mass

First, calculate moles needed from molarity and volume:

n (moles) = M (mol/L) × V (L)

Then multiply by molar mass to get mass:

mass (g) = n (mol) × molar mass (g/mol)

Unit Conversions

Common conversions: 1 L = 1000 mL = 1,000,000 µL; 1 M = 1000 mM = 1,000,000 µM = 1,000,000,000 nM; 1 g = 1000 mg = 0.001 kg

Frequently Asked Questions

What's the difference between molarity and molality?

Molarity (M) is moles of solute per liter of solution, while molality (m) is moles of solute per kilogram of solvent. Molarity depends on temperature (because volume changes), while molality does not.

How do I find the molar mass of a compound?

Sum the atomic masses of all atoms in the molecular formula. For example, NaCl: Na (22.99) + Cl (35.45) = 58.44 g/mol. You can find atomic masses on the periodic table.

Can I use this calculator for dilution calculations?

Yes! Use the volume calculator mode. If you have a stock solution of known molarity and want to dilute it, enter the desired final molarity and volume to find the volume of stock solution needed.

Why are my calculations shown in scientific notation?

Scientific notation (e.g., 1.5e-3 = 0.0015) is used for very large or very small numbers to maintain precision and readability. This is standard practice in chemistry and scientific calculations.

Is this calculator accurate enough for lab work?

Yes, this calculator uses precise mathematical formulas and provides results to 4 significant figures. However, always double-check critical calculations and consider measurement uncertainties in your actual lab work.