Chemistry

Chemical Equation Balancer

Intelligent virtual tutor. Learn the balancing method step by step or practice by adjusting coefficients interactively with real-time feedback.

Stoichiometry Conservation of Mass Combustion Synthesis Neutralization
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Type a chemical equation or select an example from the bank to begin.

About This Simulator

Chemical equations are balanced by adjusting the stoichiometric coefficients of reactants and products so that the number of atoms for each element is conserved on both sides, following the Law of Conservation of Mass. This simulator analyzes your equation and uses an algebraic solver (Gauss-Jordan) to find the smallest set of whole-number coefficients.

Beyond computing the answer, the simulator explains the reasoning: it detects the reaction type (combustion, synthesis, neutralization, displacement…) and applies discipline-specific pedagogical rules to show the balancing sequence a teacher would use — not just the algorithm's output.

How to Use

  1. Enter an equation. Type the unbalanced chemical equation using -> as the arrow and + to separate species. Example: CH4 + O2 -> CO2 + H2O.
  2. Choose a mode. Learning Mode walks you through each step with explanations. Training Mode lets you adjust coefficients yourself and get real-time feedback.
  3. Click Analyze. Or select a preset from the Exercise Bank to load it directly.
  4. Follow the steps (Learning) or try to balance it yourself (Training) using the Atom Count table as your guide.

Understanding the Results

Equation Display & Molecular View

The header shows the current equation with its active coefficients. The molecular view renders each species as colored circles representing the atoms — useful for visualizing how atom counts change as you adjust coefficients.

Step-by-Step Timeline (Learning Mode)

Each step focuses on one element at a time, following a didactic order specific to the reaction type. For combustion, for example, carbon is balanced first, then hydrogen, and oxygen last. The atom count table updates at each step to show progress.

Atom Count Table

Shows the number of atoms of each element on both sides of the equation under the current coefficients. A green "Balanced" badge means both sides match. Red "Unbalanced" and blue "Excess" indicators show where adjustments are still needed.

Frequently Asked Questions

Why are my coefficients reduced to smaller numbers?
A balanced equation should always use the simplest (lowest) integer ratio. If the solver finds 4H2 + 2O2 → 4H2O, it divides by 2 to give 2H2 + O2 → 2H2O. This is the chemical convention — using multiples is mathematically correct but not standard.
What reaction types does this simulator support?
The simulator detects and explains: organic combustion, simple synthesis, decomposition, single and double displacement, acid-base neutralization, and inorganic reactions with polyatomic ions. The didactic order of element balancing adapts automatically to each type.
How do I enter polyatomic groups like Ca(OH)2?
Use standard chemical notation with parentheses: Ca(OH)2. The parser handles nested groups and subscripts correctly. Example: Ca(OH)2 + HCl -> CaCl2 + H2O.
What are the limitations of this simulator?
The simulator targets overall stoichiometric balancing. It does not support half-reactions with explicit electrons, net ionic equations, or multi-step reaction mechanisms. Ambiguous or non-standard compound notation may cause parse errors.