Quantitative chemistry requires exact numerical results: the precise concentration of a solution, the molecular weight of a compound, the pH of an acid or base. These calculators use IUPAC 2021 standard atomic masses and established formulas to give reliable answers every time.

Three Chemistry Calculators

Molarity Calculator - Molarity M = moles / litres = (mass in g ÷ molar mass) ÷ volume in litres. Three modes: find molarity from mass and volume, find mass for a target molarity and volume, or find volume for a given mass and target molarity. Also handles dilution using M₁V₁ = M₂V₂. The molar mass needed for input comes from the Molecular Weight Calculator.

Molecular Weight Calculator - Parses chemical formulas including parentheses and subscripts - Ca(OH)₂, Al₂(SO₄)₃, C₁₂H₂₂O₁₁ - using IUPAC 2021 standard atomic masses for all 118 elements. Returns molecular weight in g/mol and elemental composition percentages. The essential input for any molarity calculation.

pH Calculator - pH = −log₁₀[H⁺]. Modes: find pH from [H⁺], find [H⁺] from pH (reverse: [H⁺] = 10^(−pH)), find pOH (pOH = 14 − pH at 25°C), and classify acid/base/neutral. Also accepts [OH⁻] as input using Kw = 1.0 × 10⁻¹⁴ at 25°C. The logarithm used here is the same as in the Logarithm Calculator.

Dilution Calculator - Apply C₁V₁ = C₂V₂ to plan any solution dilution: find required final volume, final concentration after dilution, or back-calculate stock concentration. Also generates serial dilution tables (up to 12 steps, any dilution factor) for microbiology, pharmacology, and analytical chemistry. Reuses shared chemistry utilities.

Molality Calculator - Calculate molality (mol/kg) from solute mass and molar mass, find how many grams of solute to weigh out for a target molality, and predict colligative property changes - boiling point elevation (ΔTb = i × Kb × m) and freezing point depression (ΔTf = i × Kf × m) - for water, benzene, ethanol, acetone, cyclohexane, acetic acid, or any custom solvent with known Kb and Kf.

Stoichiometry Calculator - Calculate mole ratios between reactants and products, convert grams of a reactant to grams of product using the three-step mole roadmap (g → mol → ratio → mol → g), and identify the limiting reagent from available moles of two reactants. Step-by-step working shown for every mode.

How These Calculators Connect

Example: preparing a buffer solution - (1) Use the Molecular Weight Calculator to find the molar mass of your solute. (2) Feed that into the Molarity Calculator to find how many grams to weigh out for your target concentration. (3) After mixing, use the pH Calculator to verify the [H⁺] matches your target pH.

Frequently Asked Questions

How do I prepare a 1 M solution of NaCl?

Molar mass of NaCl = 58.44 g/mol (from the Molecular Weight Calculator). For 1 L of 1 M solution, dissolve 58.44 g of NaCl in water and make up to 1,000 ml. Verify using the Molarity Calculator.

What atomic masses does the molecular weight calculator use?

The Molecular Weight Calculator uses IUPAC 2021 standard atomic weights: H = 1.008, C = 12.011, N = 14.007, O = 15.999, Na = 22.990, S = 32.06, Cl = 35.45, Ca = 40.078, Fe = 55.845.

What is the relationship between pH and pOH?

pH + pOH = 14 at 25°C, derived from Kw = [H⁺][OH⁻] = 1.0 × 10⁻¹⁴. So pH 3 means pOH = 11. The pH Calculator shows both values simultaneously.

Can the molarity calculator handle dilution calculations?

Yes. Switch to the dilution mode in the Molarity Calculator and enter any three of M₁, V₁, M₂, V₂ to find the fourth. Example: 5 ml of a 5 M stock solution diluted to 250 ml gives a 0.1 M working solution.