Home · A-Level Chemistry 9701 · An introduction to AS Level organic chemistry · Organic formulae and functional groups · Practice
AS · Practice questions · Organic formulae and functional groups

Draw it every way.

Six original Cambridge-style questions on organic formulae and functional groups.

Original questions All questions on this page are original work, written in the Cambridge AS & A Level style. They are not from past papers. They test the same concepts and skills the syllabus rewards.
Keep these straight

Every carbon makes four bonds.

01
Recall
[3 marks]

For but-1-ene give (a) the molecular formula, (b) the structural formula and (c) the empirical formula.

  • (a) C4H8. ✓
  • (b) CH2=CHCH2CH3. ✓
  • (c) CH2. ✓
02
Analysis
[2 marks]

Draw the displayed formula of ethanoic acid and name its functional group.

  • H3C–C(=O)–O–H with all C–H bonds shown. ✓
  • Carboxylic acid group, –COOH. ✓
03
Analysis
[2 marks]

A skeletal formula shows a four-carbon chain with a C=O at the end carbon. Name the functional group and give the molecular formula.

  • Aldehyde (–CHO): butanal. ✓
  • C4H8O. ✓
04
Recall
[2 marks]

State two features of a homologous series.

  • Same general formula and the same functional group. ✓
  • Successive members differ by CH2; similar chemical properties and a trend in physical properties. ✓
05
Analysis
[3 marks]

Classify each alcohol as primary, secondary or tertiary: (a) butan-1-ol, (b) butan-2-ol, (c) 2-methylpropan-2-ol.

  • (a) primary. ✓
  • (b) secondary. ✓
  • (c) tertiary. ✓
06
Analysis
[2 marks]

Identify all the functional groups in CH2=CHCH2OH and in HOOCCH2NH2.

  • CH2=CHCH2OH: alkene (C=C) and primary alcohol (–OH). ✓
  • HOOCCH2NH2: carboxylic acid (–COOH) and amine (–NH2). ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.