Chemistry
Molar mass, concentration, dilution and pH, plus the stoichiometry that connects them. 26 tools, including Beer-Lambert law calculator, Boiling point calculator (altitude & pressure), Boiling point elevation calculator and Caffeine Half-Life Tracker. All free, with no account and nothing to install.
Beer-Lambert law calculatorSolve the Beer-Lambert law A = ε·c·l for any variable — absorbance, molar absorptivity, concentration or path length. Central to spectrophotometry, it links how much light a solution absorbs to how concentrated it is. Pick what to solve for, enter the rest, and read the answer.Boiling point calculator (altitude & pressure)Find the boiling point of water at any altitude or atmospheric pressure. Water boils below 100 °C as you climb because the air pushes down less — this tool converts altitude to pressure with the barometric formula, then to a boiling point via the Clausius-Clapeyron relation. Vital for high-altitude cooking and canning.Boiling point elevation calculatorCompute how much a dissolved solute raises a solvent's boiling point: ΔTb = i·Kb·m, with i the van't Hoff factor, Kb the ebullioscopic constant and m the molality. It returns the elevation and the new boiling point — why salted pasta water boils a touch hotter.Caffeine Half-Life TrackerModel caffeine as exponential decay over your drinks to get the level at bedtime and when it clears.Chemical Equation BalancerBalance any chemical equation instantly by solving the element matrix exactly — even tricky redox reactions.Dilution calculator (C1V1 = C2V2)Find the final volume needed to dilute a solution to a target concentration.Empirical Formula CalculatorFind the empirical (and molecular) formula from mass percentages or experimental masses.Freezing point depression calculatorCompute how much a dissolved solute lowers a solvent's freezing point: ΔTf = i·Kf·m, where i is the van't Hoff factor, Kf the cryoscopic constant and m the molality. It returns the depression and the new freezing point — the physics behind salting icy roads and antifreeze.Half-life calculatorCompute how much of a substance remains after a time, given its half-life.Henderson-Hasselbalch calculatorWork with the Henderson-Hasselbalch equation pH = pKa + log₁₀([A⁻]/[HA]) for buffer solutions. Find the pH of a buffer, the base-to-acid ratio needed to hit a target pH, or the pKa from a measured pH — the everyday maths of preparing biological and chemical buffers.Ideal gas law calculatorCompute the pressure of a gas from moles, temperature and volume (PV = nRT).Limiting Reactant CalculatorDetermine which reactant runs out first from the amounts you have and the balanced equation's mole ratios.Molality calculatorCompute molality — moles of solute per kilogram of solvent — the concentration unit that, unlike molarity, does not change with temperature. Enter moles directly or a mass with its molar mass, plus the solvent mass, and it returns the molality in mol/kg.Molar Mass CalculatorCompute the molar mass of any chemical formula, with per-element composition.Molarity calculatorCompute the molar concentration of a solution from moles and volume.Mole/Gram/Particle ConverterConvert between moles, grams and number of particles using molar mass and Avogadro's number.Moles calculatorCompute the number of moles of a substance from its mass and molar mass.Normality calculatorCompute the normality of a solution — gram-equivalents of solute per litre. Enter equivalents directly or a mass with its molar mass and n-factor, plus the volume, and it returns the normality (N) and the equivalent molarity (M = N ÷ n-factor).Osmotic pressure calculatorCompute osmotic pressure with the van't Hoff equation Π = i·M·R·T — the pressure that drives water across a semipermeable membrane. Enter molarity, temperature and the van't Hoff factor to get the pressure in atmospheres, kilopascals, bar and mmHg. Key to IV fluids, cells and reverse osmosis.Percent yield calculatorCompute the percent yield of a reaction from the actual and theoretical yield.Interactive Periodic TableExplore the 118 elements — click any element for its atomic number, mass, category and properties.pH calculatorCompute the pH and pOH of a solution from the hydrogen ion concentration.PPM calculatorCompute a concentration in parts per million from a solute and solution amount.Stoichiometry CalculatorConvert between grams, moles and liters at STP across a balanced equation using mole ratios.Theoretical Yield CalculatorFind the theoretical yield of a product from reactant amounts, plus the limiting reactant and percent yield.Titration calculatorSolve acid-base titrations with the equivalence relation M₁V₁n₁ = M₂V₂n₂, which accounts for polyprotic acids and bases through their equivalents. Find an unknown analyte molarity from the titrant used, or the volume of titrant needed to reach the equivalence point.