Andre is predicting the products of chemical reactions. in one reaction, a hydrocarbon is the only reactant. what is the best prediction and explanation of this reaction? two new compounds form as the hydrocarbon undergoes a synthesis reaction. carbon dioxide and water form because the hydrocarbon undergoes a combustion reaction. a polymer forms because the hydrocarbon joins with itself in a polymerization reaction. oxides form because the hydrocarbon combines with oxygen in an oxidation reaction.