Molarity Calculator — Concentration, Moles & Dilution
Calculate molarity, moles, or volume from any two known values. Also includes the dilution calculator (C1V1=C2V2) for preparing solutions.
Enter any two values to calculate the third.
g/mol
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Step-by-Step
Common Molarity Values
Concentrated HCl~12 M
Concentrated H₂SO₄~18 M
Seawater NaCl~0.6 M
Human blood NaCl~0.15 M
Standard NaOH1 M or 0.1 M
Frequently Asked Questions
What is molarity?
Molarity (C) is the concentration of a solution, defined as moles of solute divided by litres of solution: C = n/V. Units: mol/L (also written M, e.g., "0.5 M HCl"). Higher molarity = more concentrated solution.
What is the difference between molarity and molality?
Molarity (C = n/V) uses volume of solution (litres) and changes with temperature. Molality (m = n/kg solvent) uses mass of solvent and is temperature-independent. For dilute aqueous solutions, they are approximately equal.
How do you calculate moles from molarity?
n = C × V. For example, 2 L of 0.5 M NaCl contains 0.5 × 2 = 1 mole of NaCl. Remember: volume must be in litres for this formula. To convert mL to L, divide by 1000.
What is the dilution formula C₁V₁ = C₂V₂?
When diluting a solution, the moles of solute remain constant: C₁V₁ = C₂V₂. Where C₁, V₁ are initial concentration and volume; C₂, V₂ are final. Example: How much 6 M HCl is needed to make 500 mL of 0.5 M? V₁ = (0.5 × 0.5)/6 = 0.042 L = 41.7 mL.
How do you convert between molarity and mass concentration?
Mass concentration (g/L) = Molarity × Molar Mass. For example, 0.1 M NaCl (molar mass = 58.44 g/mol) = 0.1 × 58.44 = 5.844 g/L. Conversely, molarity = (mass concentration) / (molar mass).