Question

Write the balanced chemical equation for the combustion of nonane.

Short answer

C9H20 + 14O2 -> 9CO2 + 10H2O

Step-by-step solution

Write the Unbalanced Chemical Equation

First, write the general form of the combustion reaction for nonane, which involves reacting it with oxygen to form carbon dioxide and water. Nonane is a hydrocarbon with the formula \( \text{C}_9\text{H}_{20} \). Thus, the unbalanced chemical equation is: \( \text{C}_9\text{H}_{20} + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \).

Balance the Carbon Atoms

Count and balance the carbon atoms. In nonane, there are 9 carbon atoms, so you will need 9 carbon dioxide molecules to balance the carbon atoms on both sides of the equation: \( \text{C}_9\text{H}_{20} + \text{O}_2 \rightarrow 9\text{CO}_2 + \text{H}_2\text{O} \).

Balance the Hydrogen Atoms

Nonane has 20 hydrogen atoms. Since each water molecule has 2 hydrogen atoms, you need 10 water molecules to balance the hydrogen: \( \text{C}_9\text{H}_{20} + \text{O}_2 \rightarrow 9\text{CO}_2 + 10\text{H}_2\text{O} \).

Balance the Oxygen Atoms

Count the total number of oxygen atoms needed on the product side. You have 9\( \text{CO}_2 \) which gives 18 oxygen atoms, and 10 water molecules contributing 10 oxygen atoms, making a total of 28 oxygen atoms required. Therefore, you need 14 \( \text{O}_2 \) molecules on the reactant side to balance the equation: \( \text{C}_9\text{H}_{20} + 14\text{O}_2 \rightarrow 9\text{CO}_2 + 10\text{H}_2\text{O} \).

Verify the Balanced Equation

Verify that the equation is balanced by recounting the atoms. You should have 9 carbon, 20 hydrogen, and 28 oxygen atoms on both sides: \( \text{C}_9\text{H}_{20} + 14\text{O}_2 \rightarrow 9\text{CO}_2 + 10\text{H}_2\text{O} \).

Key concepts

Combustion Reaction

A combustion reaction is a chemical reaction where a substance, typically a hydrocarbon, combines with oxygen to produce heat and light, often in the form of fire. The main products of a complete combustion reaction are carbon dioxide and water. Incomplete combustion may produce additional substances like carbon monoxide or soot.

Combustion is highly exothermic, releasing a large amount of energy, which is why it is used as a primary method for energy generation.

• Oxygen is necessary for combustion and acts as an oxidizing agent.
• Hydrocarbons, such as nonane, are common fuel sources for these reactions.
• Reactions can be used in practical applications like car engines and power plants.

Balancing a combustion reaction requires ensuring the same number of each type of atom on both sides of the equation. This ensures matter is conserved following the law of conservation of mass.

Understanding the principles of combustion reactions is essential for studying energy production and environmental impacts.

Hydrocarbons

Hydrocarbons are organic compounds composed exclusively of carbon and hydrogen atoms. They form an essential class of compounds in chemistry due to their prevalence in fuels like gasoline and diesel. Hydrocarbons can be saturated or unsaturated, with nonane being an example of a saturated hydrocarbon known as an alkane.


Saturated hydrocarbons have single bonds between carbon atoms, making them more stable and less reactive. Alkanes, such as nonane (\( ext{C}_9 ext{H}_{20}\)), are part of a homologous series with a general formula \( ext{C}_n ext{H}_{2n+2}\).

• Alkanes exhibit tetrahedral geometry around their carbon atoms.
• They are generally nonpolar, making them insoluble in water.
• Combustion is a common chemical reaction involving hydrocarbons.

Knowledge of hydrocarbons is vital for understanding both natural processes and industrial applications, as they play a significant role in the chemical and petrochemical industries.

Stoichiometry

Stoichiometry is a branch of chemistry that deals with the quantitative relationships of reactants and products in chemical reactions. It allows chemists to predict the amounts of substances consumed and formed during a reaction, based on balanced chemical equations.

The basic principle is to use the law of conservation of mass to ensure that the number of atoms of each element is the same on both sides of the equation. In the combustion of nonane, stoichiometry helps to determine the exact amounts of oxygen needed and the products formed.

• Stoichiometry involves mole-to-mole conversion using the coefficients in balanced chemical equations.
• It is essential for calculating reactant or product quantities in chemical processes.
• Helps chemists in optimizing reactions for desired yields.

Mastering stoichiometry is crucial for any student of chemistry, as it connects theoretical concepts with practical applications.