Here's how to write the balanced equation for the combustion of butane:

1. Write the unbalanced equation:

Butane (C₄H₁₀) + Oxygen (O₂) → Carbon Dioxide (CO₂) + Water (H₂O)

2. Balance the carbon atoms:

C₄H₁₀ + O₂ → 4CO₂ + H₂O

3. Balance the hydrogen atoms:

C₄H₁₀ + O₂ → 4CO₂ + 5H₂O

4. Balance the oxygen atoms:

C₄H₁₀ + 13/2 O₂ → 4CO₂ + 5H₂O

5. (Optional) Multiply to get whole numbers:

2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O

The balanced equation is:

2C₄H₁₀ (l) + 13O₂ (g) → 8CO₂ (g) + 10H₂O (g)

Key points:

* (l) denotes liquid state

* (g) denotes gaseous state