Organic Chemistry Functional Groups Quiz

Functional Groups

• Functional groups are specific groups of atoms within molecules that are responsible for characteristic chemical reactions.
• Different families of organic compounds are defined by these groups

Alkanes

• Composed of only carbon and hydrogen atoms
• All bonds are single bonds
• Example: A molecule with four carbon atoms, methane (CH₄)
• The chemical formula for an alkane with n carbon atoms is CₙH₂ₙ₊₂

Alkenes

• Contains a carbon-carbon double bond
• Only hydrogen and carbon atoms
• Example: A molecule with two carbon atoms in a double-bond.

Cycloalkanes

• Cyclic hydrocarbons; a ring structure
• Only single bonds between carbon atoms
• Example: Cyclohexane (C₆H₁₂)

Alcohols

• Molecules with an -OH group.
• Classified as primary (1°), secondary (2°), or tertiary (3°) based on the carbon atom to which the -OH group is attached.
• Example: Ethanol (C₂H₅OH), a primary alcohol

Phenols

• Contains an -OH group directly attached to an aromatic ring
• Example: A benzene ring with an -OH group (phenol).

Aldehydes

• Contains a carbonyl group (C=O) at the end of the carbon chain
• So, the carbonyl group is next door to a hydrogen atom
• Example: A molecule with two carbon atoms and an aldehyde functional group
• Aldehydes are easily oxidised to form carboxylic acids

Ketones

• Contains a carbonyl group (C=O) that is not at the end of the carbon chain
• It is directly adjacent to two carbons
• Example: A molecule with three carbon atoms and a ketone functional group

Carboxylic Acids

• Contains two oxygens (O)
• Has an O-H and a C=O group on the same carbon
• This -COOH group must be at the end of the carbon chain
• Example: Ethanoic acid (CH₃COOH)

Esters

• Contains two oxygens (O)
• One oxygen is part of a C=O bond
• The other oxygen is next door and "sandwiched" between two carbon atoms
• Example: Methyl ethanoate

Ethers

• Contains one oxygen (O) that sits between two carbon atoms (sandwiched)
• Does not contain -OH or C=O groups -Example: A molecule with two carbon atoms and an ether functional group