Chemistry calculator and periodic table
An interactive periodic table, molar mass, equation balancing, stoichiometry, solutions and gas laws in one place. Type a formula such as Ca(OH)2 or CuSO4·5H2O, or an equation such as C3H8 + O2 -> CO2 + H2O; every result updates as you type.
Tap an element to see it here, or open its page. Switch the colouring above — category, state at any temperature, electronegativity, radius, ionisation energy, melting point, density, block or year of discovery.
Capitals matter: Co is cobalt, CO is carbon monoxide. Brackets ( ) [ ] { }, hydrates with · or . or *, charges as ^2-.
Empirical and molecular formula from percentages
Write -> or = between the sides and + between substances. Ions: Fe^3+, SO4^2-, OH-; an electron is e-. Coefficients you type are checked and replaced by the smallest whole numbers.
Enter what you have of one or more reactants — in grams or moles. The one that runs out first is the limiting reactant; products are what forms if it reacts completely. Add the mass you actually obtained to get the percentage yield.
Grams, moles, particles and gas volume
c = n / V and n = m / M. Leave the formula empty to type a molar mass yourself.
C₁V₁ = C₂V₂ — any concentration unit works if both sides use the same one. Add the acid to the water, not the water to the acid.
Same solute in both. Volumes are taken as additive, which is close enough for dilute solutions.
% w/w = solute ÷ solution × 100. With a density and a formula you also get molarity; molality uses the solvent mass. The last row converts mg/L and mol/L for the formula above.
PV = nRT with R = 8.314 J/(mol·K) = 0.08206 L·atm/(mol·K). Real gases deviate at high pressure and low temperature.
P₁V₁/T₁ = P₂V₂/T₂ for a fixed amount of gas. Temperatures are converted to kelvin; pressure and volume use the units chosen above on both sides.
Each gas’s partial pressure = its mole fraction × the total. The example is dry air by mole fraction.
M = mRT / (PV). Density ρ = PM / (RT) at the same pressure and temperature.
Everything is computed in your browser; nothing you type is sent or stored. Atomic weights are IUPAC standard values; elements with no stable isotope use the mass number of the longest-lived isotope, shown in brackets.
Inside this calculator
Periodic table
All 118 elements, coloured by category, state at any temperature you choose, electronegativity, atomic radius, ionisation energy, melting point, density, block or year of discovery. Every element has its own page.
Molar mass
Molar mass and percentage composition of any formula, with brackets, hydrates and ions — and the empirical and molecular formula from percentages.
Equation balancer
Smallest whole-number coefficients for any reaction, including redox and ionic equations with charges and electrons, with an atom-by-atom check.
Stoichiometry
Limiting reactant, how much of each product forms, what is left over, theoretical and percentage yield; grams, moles, particles and gas volume.
Solutions
Molarity, dilution (C₁V₁ = C₂V₂), mixing two solutions, percent by mass, ppm and molality.
Gas laws
Ideal gas law, combined gas law, Dalton’s partial pressures, and the molar mass and density of a gas, in the units you use.
Elements
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Atomic weights: IUPAC CIAAW. Element properties: PubChem (U.S. National Library of Medicine, public domain). More tools: Tools for students.