Identify the combustion reaction. c4h12 + 7o2 ⟶ 6h2o + 4co2 2h2 + o2 ⟶ 2h2o al2s3 ⟶ 2al + 3s cl2 + 2kbr ⟶ 2kcl + br2

From the given equations, the combustion reaction is;

C₄H₁₂ + 7O₂ - - > 4CO₂ + 6H₂O

Combustion reactions are when organic compounds react with O₂ to produce water and CO₂. From the given reactions, C₄H₁₂ is an organic compound that reacts with O₂ to produce water and CO₂.

Therefore this is the only reaction that follows the general equation for combustion.