Ch.3 - Chemical Reactions and Reaction Stoichiometry

Brown - Chemistry: The Central Science 14th Edition

Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook

Brown 14th Edition

Ch.3 - Chemical Reactions and Reaction Stoichiometry

Problem 76a

Chapter 3, Problem 76a

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.

Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780134414232

Verified step by step guidance

Start by writing the unbalanced chemical equation for the combustion of propane: \( \text{C}_3\text{H}_8 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \)

Balance the carbon atoms first. Propane has 3 carbon atoms, so you need 3 \( \text{CO}_2 \) molecules: \( \text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + \text{H}_2\text{O} \)

Next, balance the hydrogen atoms. Propane has 8 hydrogen atoms, so you need 4 \( \text{H}_2\text{O} \) molecules: \( \text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O} \)

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 \( \text{H}_2\text{O} \)): \( \text{C}_3\text{H}_8 + 5\text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O} \)

Verify that all atoms are balanced: 3 carbon atoms, 8 hydrogen atoms, and 10 oxygen atoms on both sides of the equation.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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.

Recommended video:

Guided course

01:16

Stoichiometry Concept

Related Practice

Textbook Question

Consider the mixture of propane, C3H8, and O2 shown here. (c) How many molecules of CO2, H2O, C3H8, and O2 will be present if the reaction goes to completion?

954

views

Textbook Question

Aluminum hydroxide reacts with sulfuric acid as follows: 2 Al1OH231s2 + 3 H2SO41aq2¡Al21SO4231aq2 + 6 H2O1l2 How many moles of the excess reactant remain after the completion of the reaction?

624

views

Textbook Question

Consider the mixture of ethanol, C2H5OH, and O2 shown in the accompanying diagram. (c) How many molecules of CO2, H2O, C2H5OH, and O2 will be present if the reaction goes to completion?

690

views

Textbook Question

Consider the mixture of ethanol, C2H5OH, and O2 shown in the accompanying diagram. (b) Which reactant is the limiting reactant?

598

views

Textbook Question

Aluminum hydroxide reacts with sulfuric acid as follows: 2 Al1OH231s2 + 3 H2SO41aq2¡Al21SO4231aq2 + 6 H2O1l2 Which is the limiting reactant when 0.500 mol Al1OH23 and 0.500 mol H2SO4 are allowed to react?