AI Study Guru🧪 Chemical Equation Balancer
Enter any unbalanced chemical equation. Get instant balanced coefficients and reaction types for Class 10 & 12 Boards.
Why equations must balance
Balancing rests on one law: the law of conservation of mass. Atoms are neither created nor destroyed in a chemical reaction — they only rearrange. So the count of each element must be identical on both sides. A balanced equation is not a style choice; it is the only chemically honest description of the reaction, and it is the first thing a board evaluator checks before awarding any marks to the answer.
The method this balancer uses: trial with inspection order
- Write correct formulas first. H₂O stays H₂O — never change subscripts to balance; only coefficients change.
- Count atoms per element on both sides. Polyatomic ions that appear unchanged on both sides (like SO₄²⁻ or NO₃⁻) can be balanced as one unit.
- Balance the most complex compound first, then elements appearing in single compounds, and leave free elements (H₂, O₂, metals) for last.
- Clear fractions by multiplying the whole equation, then recount everything once.
Worked example — burning propane
Unbalanced: C₃H₈ + O₂ → CO₂ + H₂O. Balance carbon: 3 CO₂. Balance hydrogen: 4 H₂O. Now count oxygen: right side has 3×2 + 4×1 = 10, so O₂ gets coefficient 5. Final: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O. Count again: 3 C, 8 H, 10 O on each side — balanced.
Notice the order: C and H (bound in single compounds) first, O (free molecule) last. That ordering solves most textbook equations in under a minute.
What balancing unlocks next
Balanced equations are the start of stoichiometry: the coefficients give mole ratios, which convert between mass, moles, volume of gases at STP (22.4 L per mole) and limiting-reagent questions. A typical board numerical — “what mass of CO₂ forms when 11 g of propane burns?” — flows directly from those coefficients: 44 g propane → 3 × 44 = 132 g CO₂, so 11 g gives 33 g.
Reaction types matter too: combination, decomposition, displacement, double displacement, and redox. The balancer's output notes the reaction type so you can file examples under the right heading before the exam.
Common mistakes to avoid
- Changing subscripts (H₂O → H₂O₂) to force a balance — that changes the chemical itself.
- Balancing O or H first in combustion equations — always the slow path.
- Forgetting to recount after the final coefficient — one wrong count undoes the whole answer.
Stuck on a specific equation or a stoichiometry numerical? Send it as a photo on WhatsApp and get the steps explained at your class level.