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Year 9 Science Chemical Sciences AC9S9U02

Organic Chemistry: Functional Groups

Organic chemistry studies carbon-based compounds. Functional groups are specific clusters of atoms within a molecule that determine its chemical behaviour and reactions.

What You Need to Know

Key Concept Diagram

Hydrocarbons contain only C and H; alkanes (single bonds), alkenes (double bonds)

Hydroxyl group (-OH) characterises alcohols (e.g. ethanol)

Carboxyl group (-COOH) characterises carboxylic acids (e.g. acetic acid)

Functional groups determine physical properties like boiling point and solubility

Key Vocabulary

Functional group

A specific group of atoms within a molecule that determines its characteristic reactions

Hydrocarbon

A compound containing only carbon and hydrogen atoms

Alcohol

An organic compound containing a hydroxyl (-OH) functional group

Carboxylic acid

An organic compound containing a carboxyl (-COOH) functional group

Knowledge Check

Select the correct answer for each question. Click "Check Answer" to see if you are right.

Question 1

Which functional group is present in all alcohols?

Question 2

Ethanol (C2H5OH) and propanol (C3H7OH) are both alcohols because they both contain:

Question 3

Acetic acid (vinegar) has the formula CH3COOH. What functional group makes it an acid?

Key Concepts Summary