Balancing Chemical Equations Class 10: Steps and Example

A reliable balancing routine

1. 1

   Write correct formulas

   Name the reactants and products, then check their formulas before balancing.

2. 2

   Count each element

   Make separate left and right totals; multiply all atoms in a formula by its coefficient.

3. 3

   Adjust coefficients

   Balance an element, recount, and keep the formulas unchanged.

4. 4

   Reduce and verify

   Use the smallest whole-number coefficient ratio and check every element again.

An original worked route

Consider aluminium reacting with oxygen to form aluminium oxide: Al + O₂ → Al₂O₃. Oxygen counts of 2 and 3 suggest using 6 oxygen atoms on each side. Put 3 before O₂ and 2 before Al₂O₃. The right side now has 4 aluminium atoms, so put 4 before Al. The result is 4Al + 3O₂ → 2Al₂O₃.

The coefficient 2 in 2Al₂O₃ multiplies both elements: it represents 4 aluminium atoms and 6 oxygen atoms. It does not change the subscript 3 into 6 inside a single formula unit.

Verify the final equation

Swipe across the table to see all columns.

What balancing does not tell you

A balanced equation alone does not establish that a proposed reaction occurs under any chosen conditions. Include state symbols, heating, light or a catalyst when those are known and required. An equation is a model of a reaction, not permission to perform it at home.

If your counts will not balance, first recheck the formulas rather than making increasingly large coefficients. When revising, circle coefficients in one colour and subscripts in another to make their different roles visible.

Choose what to study next

Sources and scope

This is a focused learning resource, not a complete chapter or a prediction of board questions. Use your current syllabus and the paper-specific marking scheme for assessment requirements.