Chemical Equation
Balancer
Balance equations, learn step-by-step, and calculate stoichiometry with limiting reagents.
Free Online Chemical Equation Balancer
Balance any chemical equation instantly with step-by-step explanations and a stoichiometry calculator. Enter reagent amounts to find the limiting reagent, calculate moles and masses.
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Step-by-step
Stoichiometry
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How to Use
Tip: Use parentheses like Ca(OH)2 and charges like SO4^2-
Supported Reactions
- Combustion — burning reactions
- Synthesis — combining reactions
- Decomposition — breakdown reactions
- Redox — electron transfer
- Acid-Base — neutralization
Frequently Asked Questions
What is a balanced chemical equation?
A balanced chemical equation has the same number of atoms of each element on both sides of the reaction arrow. This follows the Law of Conservation of Mass, which states that matter cannot be created or destroyed in a chemical reaction. For example, in 2H2 + O2 = 2H2O, there are 4 hydrogen atoms and 2 oxygen atoms on each side.
How do you balance a chemical equation?
To balance a chemical equation manually: 1) Write the unbalanced equation with correct formulas. 2) Count atoms of each element on both sides. 3) Add coefficients (numbers in front of formulas) to balance one element at a time. 4) Start with the most complex molecule. 5) Balance hydrogen and oxygen last. 6) Verify all elements are balanced and coefficients are the smallest whole numbers.
Why do chemical equations need to be balanced?
Chemical equations must be balanced because atoms are neither created nor destroyed during reactions - they are only rearranged. An unbalanced equation violates the Law of Conservation of Mass and does not accurately represent the reaction. Balanced equations are essential for calculating reactant and product quantities in stoichiometry.
What is stoichiometry?
Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. Using the mole ratios from a balanced equation, you can calculate how much of each substance is needed or produced. This is crucial for laboratory work, industrial processes, and understanding reaction yields.
What is a limiting reagent?
The limiting reagent (or limiting reactant) is the substance that is completely consumed first in a chemical reaction, determining the maximum amount of product that can be formed. Once the limiting reagent is used up, the reaction stops - even if other reactants remain. The leftover reactants are called excess reagents.
What types of reactions can this tool balance?
This balancer handles all types of chemical equations including combustion, synthesis, decomposition, single replacement, double replacement, acid-base, redox, and precipitation reactions. It uses matrix algebra to find the smallest whole-number coefficients for any valid chemical equation.