Demos > Balance Reaction

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Use this tool to balance either drawn chemical reactions or written chemical equations. Please read the instructions below each input. For unlimited reaction balancing and other tools to help you check your chemistry work, use ChemDoodle 2D.

Your balanced equation will be displayed here.
  • Drawn Reaction
  • Written Equation


    This tool will balance written chemical equations for you. Both reactants and products are required (for obvious reasons). Simply write out the equation following the formatting rules outlined below and press the Balance Equation button above.

    ChemDoodle will be able to balance any equation that can be balanced. Keep in mind not all equations can be balanced, and some equations have an infinite number of irreducible solutions. In some cases, there may be a solution if a reactant is moved to the product side or a product moved to the reactant side. In these cases a negative number will be provided for the coefficient. If there is more information to convey, a message will be presented upon balancing.

    Formatting Requirements

    1. Molecular entities must be defined as formulae. Atomic order does not matter.
    2. A maximum atomic multiplicity of 100 is enforced.
    3. Separate reactants and products with an equals (=) sign.
    4. Charge symbols must be written before magnitude. So Mg2+ should be written as "Mg+2", not "Mg2+".
    5. A lone electron can be included by using a lowercase "e" or a minus sign (-).
    6. Hydrates with multiplicities can be included after an asterisk (*) character.
    7. Spaces are not required.
    8. States of matter (s, aq, g) will be stripped out.
    9. Return lines are ignored.

    Example Equations

    Click to load into the above text field.

    1. Al + HCl = AlCl3 + H2
    2. Cr7N66H96C42O24 + MnO4- + H+ = Cr2O7-2 + Mn+2 + CO2 + NO3- + H2O
    3. I- = I2 + e
    4. MgSO4*7H2O = MgSO4 + H2O


This tool will balance drawn reactions for you. Both reactants and products are required (for obvious reasons). Simply draw out the reaction in the sketcher and press the Balance Reaction button above.

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