Question

when octane or dodecane reacts with oxygen to form water and carbon dioxide, what fundamental step must happen to the reactant molecules before the product molecules can be formed?

Explanation:

In chemical reactions (like the combustion of octane/dodecane with oxygen), reactant molecules must first break their existing chemical bonds. This is because chemical reactions involve the rearrangement of atoms, which requires the bonds in reactant molecules (e.g., C - C, C - H in hydrocarbons, O = O in oxygen) to be broken so that the atoms can recombine to form the product molecules (water and carbon dioxide).

Answer:

The reactant molecules (octane/dodecane and oxygen) must have their chemical bonds broken (bond breaking of reactant molecules) before new bonds can form to create the product molecules (water and carbon dioxide).