Chemistry Calculator: How to Calculate Molar Mass, Dilutions, Reaction Yield, and More

Chemistry calculations are essential whether you are a student studying for an exam, a lab technician preparing solutions, or a hobbyist working on home experiments. From molar mass and dilution factors to reaction yields and pH, our Chemistry Calculator handles the math so you can focus on the science.

Common Chemistry Calculations at a Glance

Calculation	Formula	Units	Example
Molar Mass	Sum of atomic masses	g/mol	H₂O = 18.015 g/mol
Moles	n = mass / molar mass	mol	36 g H₂O = 2 moles
Concentration	C = n / V	mol/L (M)	0.5 mol in 1 L = 0.5 M
Dilution	C₁V₁ = C₂V₂	M × L	5 M × 100 mL = 1 M × 500 mL
pH	pH = −log[H⁺]	—	[H⁺] = 10⁻⁵ → pH = 5
Reaction Yield	% yield = (actual / theoretical) × 100	%	4.5 g actual / 5.0 g theoretical = 90%
Ideal Gas Law	PV = nRT	atm, L, mol, K	1 mol at STP = 22.4 L

Practical Chemistry Problems Solved

1. Preparing a Solution of a Specific Concentration

You need 500 mL of 0.1 M sodium chloride (NaCl, molar mass 58.44 g/mol). How much NaCl do you weigh? Using n = C × V, you need 0.05 moles. Mass = 0.05 × 58.44 = 2.922 g. The Chemistry Calculator walks you through each step.

2. Diluting a Stock Solution

You have a 6 M hydrochloric acid stock solution and need 200 mL of 0.5 M HCl. Using C₁V₁ = C₂V₂: 6 × V₁ = 0.5 × 200, so V₁ = 16.7 mL of stock solution, diluted to 200 mL with water. The calculator handles the dilution math automatically.

3. Calculating Reaction Yield

You run a reaction that theoretically should produce 10 g of product, but you only recovered 7.3 g. Percent yield = (7.3 / 10) × 100 = 73%. Use the calculator to determine yield and identify where losses occurred.

Units and Conversions in Chemistry

Chemistry uses a specific set of units, and getting them right is critical:

Molarity (M) = moles per liter — the most common concentration unit
Molality (m) = moles per kilogram of solvent — used for colligative properties
Parts per million (ppm) = mg/L for dilute solutions — common in environmental chemistry
STP = Standard Temperature and Pressure (0°C, 1 atm) — 1 mole of any gas = 22.4 L

The Chemistry Calculator works with all these units and includes a built-in periodic table reference for molar mass calculations. Try it for your next lab session or study session.

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