Chemistry

Moles, molar mass, molarity, dilution and concentration.

• Dilution Calculator (C1V1 = C2V2) Solve C1V1 = C2V2 for any value, with the amount of solvent to add.
• Mass Percent Calculator Mass percent of a solute from its mass and the mass of the solvent.
• Molality Calculator Molality in mol/kg from the mass of solute and the mass of solvent.
• Molar Mass and Molecular Weight Calculator Molar mass and molecular weight from a chemical formula, with the mass percent of each element.
• Molarity Calculator Molarity of a solution from mass and volume, or the mass to weigh out for a target concentration.
• Mole Fraction Calculator Mole fraction and mole percent of each component in a mixture of up to four.
• Moles Calculator Convert between mass, moles and molar mass, with the number of particles.
• Normality Calculator Normality and equivalent weight from mass, volume and equivalents per mole.
• Parts per Million and Parts per Billion Calculator Parts per million and parts per billion from the mass of a substance and the mass of the whole.
• Percentage Concentration Calculator (w/w, w/v, v/v) Percent w/w, w/v or v/v of a solution, or the solute needed to reach a target percentage.
• Solution Concentration Calculator Convert a concentration between mol/L, mmol/L, g/L, mg/L and percent w/v.

Stoichiometry, limiting reactants, yield and empirical formulas.

• Atom Economy Calculator Atom economy of a reaction from the molar masses and coefficients in its balanced equation.
• Empirical and Molecular Formula Calculator Empirical formula from percent composition or masses, and the molecular formula from the molar mass.
• Limiting Reactant Calculator Which reactant runs out first, the product it allows and how much of the other is left over.
• Stoichiometry Calculator Mass and moles of one substance from another, using the coefficients of a balanced equation.
• Theoretical and Percent Yield Calculator Theoretical yield from the limiting reactant, and percent yield from what you actually collected.

pH, titration, buffers, Ka, Kb and equilibrium constants.

• Acid-Base Titration Calculator Unknown concentration or titrant volume at the equivalence point, using the coefficients of the balanced equation.
• Buffer Capacity Calculator Buffer capacity from total concentration, pKa and pH, using the Van Slyke equation.
• Equilibrium Constant Calculator Equilibrium constant Kc from equilibrium concentrations and the coefficients of aA + bB ⇌ cC + dD.
• Henderson-Hasselbalch Calculator Buffer pH from pKa and the conjugate base to acid ratio, or the ratio needed for a target pH.
• Ka and Kb from pH Calculator Work out Ka or Kb and the percent ionised from a measured pH and starting concentration.
• Ka, Kb, pKa and pKb Calculator Convert between Ka, Kb, pKa and pKb for a conjugate acid-base pair at 25 °C.
• pH, pOH and Hydrogen Ion Concentration Calculator Convert between pH, pOH, hydrogen ion concentration and hydroxide ion concentration.
• Reaction Quotient Calculator Reaction quotient Q from the current concentrations, compared with K to show which way a reaction will shift.
• Solubility Product (Ksp) Calculator Ksp from molar solubility, or molar solubility from Ksp, for a salt of any simple ion ratio.

Gibbs energy, enthalpy, Nernst, Faraday and reaction rates.

• Activation Energy Calculator Activation energy from rate constants measured at two temperatures.
• Arrhenius Equation Calculator Rate constant from activation energy and temperature, and how much it changes at a second temperature.
• Bond Energy Calculator Estimate a reaction’s enthalpy change from the bonds broken and the bonds formed.
• Cell Potential Calculator Standard cell potential from electrode potentials, with ΔG and the equilibrium constant.
• Electroplating Thickness Calculator Plating thickness and mass from current, time, surface area and current efficiency.
• Enthalpy Change Calculator Enthalpy change in kJ/mol from a calorimetry experiment.
• Entropy Change Calculator Entropy change of a reaction from standard entropies, or of a phase change from its enthalpy and temperature.
• Faraday’s Law of Electrolysis Calculator Mass deposited in electrolysis from current and time, or the time or current for a target mass.
• Gibbs Free Energy Calculator ΔG from enthalpy, entropy and temperature, with the equilibrium constant and crossover temperature.
• Hess’s Law Calculator Add up the enthalpies of reaction steps, each scaled or reversed, to get an overall enthalpy change.
• Nernst Equation Calculator Cell potential away from standard conditions, from E°, electrons transferred, reaction quotient and temperature.
• Radioactive Decay and Half-Life Calculator Half-life arithmetic: the amount left after a time, the time to reach an amount, or the half-life itself.
• Reaction Rate Calculator Reaction rate from a rate law and concentrations, or the average rate from a change in concentration over time.

Ideal gas law, Boyle, Charles, Gay-Lussac and gas density.

• Avogadro’s Law Calculator Solve V₁/n₁ = V₂/n₂ for a gas at constant temperature and pressure.
• Boyle’s Law Calculator Solve P₁V₁ = P₂V₂ for a fixed amount of gas at constant temperature.
• Charles’s Law Calculator Solve V₁/T₁ = V₂/T₂ for a fixed amount of gas at constant pressure.
• Combined Gas Law Calculator Solve P₁V₁/T₁ = P₂V₂/T₂ for any value, for a fixed amount of gas.
• Gas Density Calculator Density of an ideal gas from its molar mass, pressure and temperature.
• Gay-Lussac’s Law Calculator Solve P₁/T₁ = P₂/T₂ for a fixed amount of gas at constant volume.
• Ideal Gas Law Calculator (PV = nRT) Solve PV = nRT for pressure, volume, moles or temperature.
• Molar Volume of a Gas Calculator Volume of one mole of an ideal gas at any temperature and pressure.