WM ab: Organic functional groups

Question 1

Define primary, secondary and tertiary alcohols.

Answer 1

Primary: -OH group bonded to carbon which is itself bonded to 1 carbon

Secondary: -OH group bonded to carbon which is itself bonded to 2 carbons

Tertiary: -OH group bonded to carbon which is itself bonded to 3 carbons

Question 2

State whether the following alcohols are primary, secondary or tertiary.

• 2-methylpropan-2-ol
• Butan-1-ol
• Butan-2-ol

Answer 2

• Tertiary
• Primary
• Secondary

Question 3

What is a carbonyl group?

Answer 3

C=O

Question 4

• Draw the general formula of aldehydes
• By what suffix are they named?

Answer 4

-al

Carbonyl group at end of alkane chain

Question 5

• Draw the general formula of ketones
• By what suffix are they named?

Answer 5

-one

Question 6

Name the following molecules and state which homologous series they belong to.

• CH₃CHO
• CH₃COCH₃

Answer 6

• Ethanal, aldehyde
• Propanone, ketone

Question 7

• Write and draw the general formula of acid anhydrides
• How are they named?

Answer 7

• (RCO)₂O
• R groups correspond to carboxylic acid naming, e.g. ethanoic anhydride

Carboxylic acid derivatives

Question 8

• Write and draw the general formula of esters
• Explain how they are named

Answer 8

• RCOOR’
• Name alcohol-derived chain first, with “yl” suffix, then acid-derived chain, with “oate” suffix

Think of esters as an alcohol replacing the H in a carboxylic acid’s COOH

Question 9

Name this molecule.

Answer 9

Propyl ethanoate

Question 10

• State the relationship between alkanes and ethers
• Write the general formula of ethers
• Explain how they are named

Answer 10

• Ethers are alkanes with one hydrogen replaced by an alkoxy (-OR) group
• ROR’
• [Prefix for shorter alkane]oxy [name of longer alkane], e.g. methoxyethane

Question 11

• Name C₂H₅OC₄H₉
• Name CH₃C(OC₃H₇)C₃H₇

Answer 11

• Ethoxybutane
• 2-propoxypentane

Question 12

What type of isomerism is shown between ethers and alcohols?

Answer 12

Functional group structural isomerism.

Question 13

• Draw phenol.
• Give its molecular formula

Answer 13

C₆H₅OH

Question 14

Name these molecules:

Answer 14

• Benzoic acid (benzenecarboxylic acid)
• Benzene-1,4-dicarboxylic acid

Question 15

The systematic name for salicylic acid is 2-hydroxybenzoic acid. Draw its skeletal formula.

Answer 15

Question 16

The systematic name for oil of wintergreen is methyl 2-hydroxybenzoate. Draw its skeletal formula.

Answer 16

Question 17

The systematic name for aspirin is 2-ethanoyl oxybenzoic acid. Draw its skeletal formula.

Answer 17