Reaction balancing

• Algorithm

  1) Write the scheme 2) Balance metals 3) Nonmetals 4) Hydrogen 5) Oxygen 6) Verify elements by table.

• Example

  Fe₂O₃ + CO → Fe + CO₂: oxygen 3+1 → Fe₂O₃ + 3CO → 2Fe + 3CO₂ — coefficients 1,3,2,3.

• Fractional coefficients

  If O₂ comes out fractional — multiply all coefficients by 2; fractions in the final equation are forbidden.

• Electron balance

  For redox: oxidation states → electrons lost/gained → least common multiple → coefficients.

Typical mistake: changing subscripts (H₂O → H₂O₂) instead of coefficients. The subscript is the compound's formula — only the number before it changes.