Exploring Organic Chemistry: Hydrocarbons, Functional Groups, and Polymers

Introduction to Organic Chemistry

Organic chemistry is the study of compounds containing carbon atoms, which form the basis of living organisms and many materials around us. This topic covers the fundamental concepts of organic chemistry, including hydrocarbons, functional groups, and polymers.

Hydrocarbons

Hydrocarbons are organic compounds composed solely of carbon and hydrogen atoms. They can be classified into two main categories:

• Alkanes: Saturated hydrocarbons with single carbon-carbon bonds, such as methane (CH4), ethane (C2H6), and propane (C3H8).
• Alkenes: Unsaturated hydrocarbons with at least one carbon-carbon double bond, such as ethene (C2H4) and propene (C3H6).

Crude Oil and Fractional Distillation

Crude oil is a mixture of hydrocarbons formed from the remains of ancient plants and animals over millions of years. Through a process called fractional distillation, crude oil can be separated into different fractions based on their boiling points, including:

• Refinery gases (e.g., methane, ethane, propane)
• Gasoline
• Kerosene
• Diesel fuel
• Lubricating oils
• Bitumen (for road surfacing)

Properties and Reactions of Alkanes

Alkanes are relatively unreactive due to their stable, saturated carbon-carbon bonds. They exhibit properties such as:

• Low reactivity and flammability
• Generally insoluble in water but soluble in non-polar solvents
• Used as fuels and lubricants

Alkenes and Polymerization

Alkenes are more reactive than alkanes due to their carbon-carbon double bonds. They can undergo addition reactions, such as the reaction with bromine water, which results in a colorless solution turning orange-brown.

Polymerization is the process of joining many small alkene molecules together to form long-chain polymers. Common polymers include polyethene, polypropene, and polyvinyl chloride (PVC).

Worked Example: Polymerization of Ethene

The polymerization of ethene (C2H4) produces polyethene:

n C2H4 → (-CH2-CH2-)n

The "n" represents the number of ethene molecules joined together in the polymer chain.

Functional Groups and Alcohols

Functional groups are specific arrangements of atoms within a molecule that determine its chemical properties. Alcohols are organic compounds containing the hydroxyl (-OH) functional group attached to an alkyl group.

Alcohols can undergo reactions like combustion and oxidation, and they are used in various applications, such as fuels, solvents, and cleaning products.

Carboxylic Acids

Carboxylic acids are organic compounds containing the carboxyl (-COOH) functional group. They are weak acids and can undergo reactions like neutralization with bases and esterification with alcohols.

Carboxylic acids have various uses, including in food preservation, cleaning products, and the production of esters, which are commonly used as flavors and fragrances.