Acid Molarity Calculator
This acid molarity calculator computes the molar concentration of concentrated acid solutions from their density, purity percentage, and molar mass. Pre-configured for common laboratory acids including H₂SO₄, HCl, HNO₃, and H₃PO₄.
Acid Molarity Calculator
Density × Purity → Acid Molarity
M = (density × purity% × 1000) / MW What is Acid Molarity?
Acid molarity is the molar concentration of an acid in solution, expressed in moles per liter (M). Concentrated laboratory acids are sold by density and purity, so calculating their molarity requires the density-purity formula.
Common concentrated acid molarities: H₂SO₄ ≈ 18.4 M (98%, 1.84 g/mL), HCl ≈ 12.1 M (37%, 1.19 g/mL), HNO₃ ≈ 15.9 M (70%, 1.42 g/mL).
Knowing the exact molarity of concentrated acids is essential for preparing diluted working solutions, performing titrations, and ensuring stoichiometric accuracy in reactions.
Acid Molarity Formula
The formula for calculating molarity from acid molarity:
To use this formula, you need acid mass, volume, and molar mass. The calculator handles all unit conversions automatically.
Enter your values below to see the acid molarity formula in action.
Where mass is in grams (g), volume is in liters (L), and molar mass is in g/mol.
How to Calculate Acid Molarity
Follow these steps to calculate molarity from acid molarity:
- Identify the acid molarity of your solute and gather all known values.
- Find the molar mass of the substance from the periodic table or a chemical database.
- Enter your acid molarity value and select the appropriate unit from the dropdown.
- Enter the volume of the solution in liters (L) or select another volume unit.
- Click Calculate to get the molarity result instantly.
- Verify the result using the step-by-step breakdown provided by the calculator.
Acid Molarity Calculator Examples
The examples below show how to use the acid molarity calculator in practice.
Example 1: What is the molarity of concentrated sulfuric acid? Concentrated H₂SO₄: density 1.84 g/mL, 98% purity, molar mass 98 g/mol → M = (1.84 × 1000 × 0.98) / 98 ≈ 18.4 M.
Example 2: Using the formula: molarity = moles ÷ volume, compute the result and verify with the calculator above.
Example 3: Enter your own values into the calculator to see personalized step-by-step results.
Molarity Calculator Tools
Explore our collection of 20 specialized molarity calculators. Each tool is designed for a specific type of calculation with its own unique input fields and formulas.
FAQs
How do you calculate acid molarity?
M = mass of acid (g) ÷ [molar mass (g/mol) × volume (L)]. For concentrated acids, use density and % purity.
What is the molarity of concentrated sulfuric acid?
Concentrated H₂SO₄: density 1.84 g/mL, 98% purity, molar mass 98 g/mol → M = (1.84 × 1000 × 0.98) / 98 ≈ 18.4 M.
Does acid strength affect molarity?
No. Molarity measures total dissolved acid. Acid strength (Ka) measures dissociation, which is independent of molarity.
What units does the Acid Molarity Calculator support?
The acid molarity calculator supports mass units (g, mg, µg, kg), volume units (L, mL, µL, gal), molar mass (g/mol, kg/mol), and molarity units (M, mM, µM, nM, pM, fM, aM).
Is the Acid Molarity Calculator free to use?
Yes. The acid molarity calculator is 100% free, requires no sign-up, and works on all devices. All calculations are performed instantly in your browser.