Here's how to write the balanced equation for the complete combustion of 2-hexene:

1. Reactants and Products:

* Reactants: 2-hexene (C₆H₁₂) and oxygen (O₂)

* Products: Carbon dioxide (CO₂) and water (H₂O)

2. Unbalanced Equation:

C₆H₁₂ + O₂ → CO₂ + H₂O

3. Balancing the Equation:

* Carbon (C): There are 6 carbon atoms on the left side and 1 on the right. Multiply CO₂ by 6.

* Hydrogen (H): There are 12 hydrogen atoms on the left side and 2 on the right. Multiply H₂O by 6.

* Oxygen (O): There are 2 oxygen atoms on the left side and 18 on the right. Multiply O₂ by 9.

4. Balanced Equation:

C₆H₁₂ + 9O₂ → 6CO₂ + 6H₂O