Question

c₃h₈ + o₂ → h₂o + co₂ + heat is an example of a/an ____ reaction.

Explanation:

Step1: Identify the reaction type

The reaction given is the combustion of propane ($\ce{C3H8}$) with oxygen ($\ce{O2}$) to produce water ($\ce{H2O}$), carbon dioxide ($\ce{CO2}$), and heat. Combustion reactions are exothermic (release heat) and involve a hydrocarbon reacting with oxygen to form carbon dioxide and water. Also, since it releases heat, it is an exothermic reaction, and specifically, the reaction of a hydrocarbon with oxygen is a combustion reaction.

Step2: Recall reaction types

Combustion reactions are a type of oxidation - reduction (redox) reaction, but more specifically, the reaction of a hydrocarbon (like propane) with oxygen to produce $\ce{CO2}$, $\ce{H2O}$, and heat is characteristic of a combustion reaction. Also, since heat is released, it is an exothermic reaction. But the most specific type here is combustion (and exothermic). However, in the context of chemical reactions, the reaction $\ce{C3H8 + O2 -> H2O + CO2 + heat}$ is a combustion reaction (and also exothermic).

Answer:

combustion (or exothermic, but combustion is more specific for this hydrocarbon - oxygen reaction)