GCSE Chemistry: An Introduction to Organic Chemistry

What is Organic Chemistry?

Organic chemistry deals with the study of compounds containing carbon atoms, which form the basis of all living matter. This branch of chemistry explores the properties, structures, and reactions of organic compounds, many of which are essential for life processes.

Hydrocarbons

Hydrocarbons are the simplest organic compounds, consisting of carbon and hydrogen atoms only. They are classified into two main groups:

• Alkanes (saturated hydrocarbons) - These have only single carbon-carbon bonds and their general formula is CnH2n+2. They are found in crude oil and natural gas.
• Alkenes (unsaturated hydrocarbons) - These contain at least one carbon-carbon double bond and have the general formula CnH2n.

Crude Oil and Fractional Distillation

Crude oil is a mixture of many different hydrocarbons that are separated by fractional distillation. This process involves heating the crude oil until it vaporizes, then cooling and condensing the vapors at different temperatures, allowing fractions with different boiling points to be collected separately.

Functional Groups and Reactions

Functional groups are specific atom arrangements within molecules that determine their chemical properties and reactivity. Some important functional groups include:

• Alcohols - These contain the -OH group and can undergo reactions like combustion and oxidation.
• Carboxylic acids - These have the -COOH group and can react with bases to form salts, or with alcohols to form esters.

Polymers

Polymers are large molecules made up of many smaller units called monomers. They can be formed through a process called polymerization, where alkenes join together to form long chains. Polymers have a wide range of applications, including plastics, fibers, and rubber.

Worked Example: Identifying Functional Groups

Problem: Identify the functional group present in the compound CH3CH2OH.

Solution:

1. The compound contains an -OH group.
2. This is the characteristic functional group of alcohols.
3. Therefore, the compound is an alcohol with the functional group -OH.