Consider the mixture of propane, C3H8, and O2 shown here. (a) Write a balanced equation for the combustion reaction that occurs between propane and oxygen.

Verified step by step guidance

1. Start by writing the unbalanced chemical equation for the combustion of propane: \( \text{C}_3\text{H}_8 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \)
2. Balance the carbon atoms first. Propane has 3 carbon atoms, so you need 3 \( \text{CO}_2 \) molecules: \( \text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + \text{H}_2\text{O} \)
3. Next, balance the hydrogen atoms. Propane has 8 hydrogen atoms, so you need 4 \( \text{H}_2\text{O} \) molecules: \( \text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O} \)
4. Now, balance the oxygen atoms. You have 3 \( \text{CO}_2 \) molecules and 4 \( \text{H}_2\text{O} \) molecules, which means you need a total of 10 oxygen atoms (6 from \( \text{CO}_2 \) and 4 from \( \text{H}_2\text{O} \)): \( \text{C}_3\text{H}_8 + 5\text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O} \)
5. Verify that all atoms are balanced: 3 carbon atoms, 8 hydrogen atoms, and 10 oxygen atoms on both sides of the equation.

Key Concepts

Combustion Reactions

Combustion reactions are chemical processes in which a substance reacts rapidly with oxygen, producing heat and light. In organic compounds like propane, the reaction typically produces carbon dioxide and water as products. Understanding the general form of combustion reactions is essential for writing balanced equations.

Balancing Chemical Equations

Balancing chemical equations involves ensuring that the number of atoms of each element is the same on both sides of the equation. This is achieved by adjusting the coefficients of the reactants and products. A balanced equation reflects the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.

Stoichiometry

Stoichiometry is the quantitative relationship between reactants and products in a chemical reaction. It allows chemists to calculate the amounts of substances consumed and produced in a reaction. In the context of combustion, stoichiometry helps determine the precise ratios of propane and oxygen needed to achieve complete combustion.