Complete and balance each hydrocarbon combustion reaction. \begin{equation}\begin{array}{l}{\text { a. } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{3}+\mathrm{O}_{2} \longrightarrow} \\ {\text { b. } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}+\mathrm{O}_{2} \longrightarrow} \\ {\text { c. } \mathrm{CH}=\mathrm{CH}+\mathrm{O}_{2} \longrightarrow}\end{array}\end{equation}

When we talk about hydrocarbon combustion, we refer to a chemical reaction where a hydrocarbon—typically a compound consisting of carbon (C) and hydrogen (H)—reacts with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O). This reaction releases energy in the form of heat and light, which is why it is used so widely as a source of energy for various applications, including in car engines, heating systems, and power plants.

Combustion is a type of oxidation-reduction reaction where the hydrocarbon is oxidized, and the oxygen is reduced. Common fuels like propane (C₃H₈), butane (C₄H₁₀), and gasoline are hydrocarbons that undergo combustion. For the reaction to occur, a source of ignition, such as a spark or heat, is usually required to initiate the process. Real-world combustion reactions can also produce other byproducts like nitrogen oxides or carbon monoxide, depending on the conditions and the presence of other elements in the fuel.

Balancing a chemical equation is a fundamental skill in chemistry. This involves ensuring that the number of atoms for each element is the same on both the reactant and product sides of the equation. According to the law of conservation of mass, atoms are not created or destroyed in a chemical reaction, so a balanced equation must reflect this principle.

The step-by-step solution above demonstrates this process in a series of stages for clarity.

Balancing Carbon Atoms

The first step is always to balance the carbon atoms since they are the basis of the hydrocarbon chain.

Balancing Hydrogen Atoms

Hydrogen atoms are the next to be balanced, followed by

Balancing Oxygen Atoms

which may require a bit of juggling, particularly since oxygen is diatomic (O₂). Note that the coefficients filled in front of the chemical formulas (the numbers indicating how many molecules are involved) must be the smallest possible integer values to satisfy balance.

Stoichiometry is a branch of chemistry that deals with the quantitative relationships of the substances involved in chemical reactions. By using the coefficients from a balanced equation, stoichiometry allows us to predict how much of a product will form from a certain amount of reactants or how much of one reactant is needed to completely react with another.

In the context of hydrocarbon combustion, stoichiometry tells us the proportion of oxygen needed to burn the hydrocarbon completely, and the amounts of carbon dioxide and water that will be produced. This concept is pivotal for ensuring that industrial processes are efficient and for predicting the environmental impact of burning hydrocarbons. The provided example demonstrates stoichiometry in action, as it gives exact measures for how much of each product is formed once the equation is balanced. An understanding of stoichiometry is not only critical for solving textbook problems but is also essential for any real-life application involving chemical reactions.