Question

What is the main component of natural gas? Write out the balanced chemical equation illustrating its combustion.

Short answer

Methane is the main component of natural gas. The balanced combustion equation is: CH₄ + 2O₂ → CO₂ + 2H₂O.

Step-by-step solution

Identifying the Main Component

Natural gas is primarily composed of methane (CH₄), although it may also contain small amounts of other hydrocarbons such as ethane, propane, and butane. For calculation purposes and chemical combustion equations, we consider methane as the primary component.

Understanding Combustion

Combustion is a chemical reaction that typically involves the reaction of a hydrocarbon with oxygen to produce carbon dioxide and water. In the case of methane, combustion will produce CO₂ and H₂O.

Writing the Chemical Equation

The general formula for the combustion reaction of methane is: CH₄ + O₂ → CO₂ + H₂O. However, this equation is not yet balanced, as the number of atoms on both sides of the equation are unequal.

Balancing the Chemical Equation

To balance the equation, start by balancing the carbon atoms: CH₄ + O₂ → CO₂ + H₂O becomes CH₄ + O₂ → CO₂ + 2H₂O to balance the hydrogen. Adjust the oxygen: CH₄ + 2O₂ → CO₂ + 2H₂O is now balanced, with 1 carbon, 4 hydrogens, and 4 oxygens on both sides.

Key concepts

Methane

Methane, with the chemical formula \( CH_4 \), is the simplest hydrocarbon and serves as the main component of natural gas. This colorless and odorless gas is not only significant in energy production but also plays a role in various environmental processes. It consists of one carbon atom bonded to four hydrogen atoms, forming a tetrahedral structure.
Methane is a potent greenhouse gas, meaning it contributes significantly to the greenhouse effect, which affects global warming. Despite this, it is a vital energy resource thanks to its high energy content, making it efficient for heating and electricity generation.
In the context of natural gas, methane is prized for its clean-burning properties, as it produces less carbon dioxide compared to other fossil fuels.

Chemical Equation Balancing

Balancing a chemical equation means ensuring that the number of each type of atom on the reactant side equals the number on the product side.
This is crucial for reflecting the conservation of matter: matter cannot be created or destroyed, only transformed. In the case of methane combustion, the chemical equation starts as \( CH_4 + O_2 \rightarrow CO_2 + H_2O \). However, initially, this equation is not balanced.

• First, balance the carbon atoms. There is one carbon in methane and also one carbon atom in carbon dioxide, so this part is balanced.
• Next, look at the hydrogen atoms. Methane has four hydrogen atoms, but water initially only has two. By making it \( 2H_2O \), the hydrogens are balanced.
• Now, adjust the oxygen atoms. The right side of the equation now has four oxygen atoms (2 in \( CO_2 \) and 2 in \( 2H_2O \)). To balance the oxygen, place a coefficient of 2 in front of \( O_2 \). This gives \( CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O \).

Balancing these equations is key to correctly describing chemical reactions.

Combustion Reaction

Combustion reactions are chemical processes that occur when a substance combines with oxygen, releasing energy in the form of heat and light. These reactions are a significant part of energy production, particularly when they involve hydrocarbons, such as methane.
In a typical combustion reaction, like that of methane, the primary products are carbon dioxide and water, highlighting the conversion of energy stored in chemical bonds.
Combustion can be complete or incomplete:

• Complete combustion occurs when the hydrocarbon burns in a sufficient supply of oxygen, producing carbon dioxide and water as products.
• Incomplete combustion happens with limited oxygen. This can lead to the production of carbon monoxide, a poisonous gas, alongside carbon dioxide and water.

For methane, the balanced equation \( CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O \) outlines a complete combustion reaction.

Hydrocarbons

Hydrocarbons are organic compounds consisting of hydrogen and carbon atoms. These are the simplest types of organic molecules and are classified into different types such as alkanes, alkenes, and alkynes.
Methane, which is an alkane, represents the simplest form of hydrocarbon, where carbon atoms form single bonds with hydrogen atoms.
Hydrocarbons are important because they serve as the main source of energy in the form of fossil fuels, like natural gas, petroleum, and coal.

• Alkanes, like methane, are saturated hydrocarbons, meaning they have only single bonds and the maximum possible number of hydrogen atoms per carbon.
• Alkenes contain at least one double bond, while alkynes have one or more triple bonds, making them unsaturated hydrocarbons.

Understanding hydrocarbons helps in grasping broader chemical concepts, especially when studying energy cycles and environmental impacts.