12. Oxidation-Reduction
1. (D) Hydrocarbon combustion reactions can be seen as redox reactions
due to the fact that an element, O 2 (with an oxidation state of 0), enters into
two compounds, CO 2 and H 2 O (with an oxidation state of −2). Elements on
one side of a reaction equation that are found in compounds on the other side
of the reaction equation mandate a transfer of electrons.