Molarity Calculator
Calculate concentration (mol/L), moles, mass, or volume for any chemical solution
Solve For
Mass of Solute (g)
g
Molar Mass (g/mol)
g/mol
Volume of Solution (mL)
mL
Molarity (mol/L)
M
Formulae
C = n / V (mol/L)
n = m / M (mol)
m = n × M (grams)
Results
Molarity (C)
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Moles (n)
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Mass (m)
—
Volume (V)
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Molarity Explained
Molarity (C) is the most common unit of solution concentration in chemistry — moles of solute per litre of solution (mol/L or M). The relationship between mass, moles, and molar mass is: n = m/M (moles = grams ÷ grams-per-mole). Combining with C = n/V gives you all four variables.
Example: To make 500 mL of 0.1 M NaCl (molar mass = 58.44 g/mol): moles needed = 0.1 × 0.5 = 0.05 mol; mass = 0.05 × 58.44 = 2.922 g. Dissolve 2.922 g NaCl in water and make up to 500 mL.
lightbulb Example
5.85 g NaCl in 500 mL:
1n = 5.85/58.44 = 0.1 mol
2C = 0.1/0.5 = 0.2 mol/L
✓ 0.2 M NaCl solution