Organic Chemistry - Fuels

Objective: State that hydrocarbons are compounds that contain hydrogen and carbon only

This section introduces the fundamental concept of hydrocarbons, which are the basis for many fuels. Understanding their composition is crucial for comprehending fuel properties and combustion.

What are Hydrocarbons?

Hydrocarbons are organic compounds composed exclusively of hydrogen (H) and carbon (C) atoms.

Chemical Formula

The general formula for a hydrocarbon is:

$$C_n H_m$$

where 'n' represents the number of carbon atoms and 'm' represents the number of hydrogen atoms.

Types of Hydrocarbons

Hydrocarbons are further classified into three main types based on the type of bonding between the carbon atoms:

• Alkanes: Contain only single bonds between carbon atoms.
• Alkenes: Contain at least one double bond between carbon atoms.
• Alkynes: Contain at least one triple bond between carbon atoms.

Examples of Hydrocarbons as Fuels

Many fuels we use are hydrocarbons. Here are some common examples:

• Methane (CH₄): A primary component of natural gas.
• Ethane (C₂H₆): Found in natural gas and produced during the decomposition of organic matter.
• Propane (C₃H₈): Used in LPG (Liquefied Petroleum Gas).
• Butane (C₄H₁₀): Used in lighters and as a component of LPG.
• Pentane (C₅H₁₂): A component of petrol (gasoline).
• Hexane (C₆H₁₄): Another component of petrol.

Table summarizing Hydrocarbon Types

Type	Bonding between Carbon Atoms	Examples
Alkanes	Single bonds	Methane, Ethane, Propane, Butane
Alkenes	Double bonds	Ethene, Propene
Alkynes	Triple bonds	Ethyne (Acetylene)

Understanding that fuels are composed of hydrocarbons is a fundamental step in analyzing their combustion and energy content. The specific type of hydrocarbon influences the fuel's properties and how efficiently it burns.