Chemistry 5070 · O Level
Formulae, functional groups and terminology
55 practice questions on Formulae, functional groups and terminology, with worked solutions and instant marking.
Which option gives the correct definition of isomers?
May/June 2015
Use any of the organic compounds listed below to answer the questions that follow. butane butanoic acid butyl ethanoate ethanol ethyl butanoate methane methanol methyl propanoate propane propanoic acid propanol Each compound may be used once, more than once, or not used at all.
May/June 2015
Use the compounds listed below to answer the questions on the opposite page. Each compound may be used once, more than once, or not at all. The compounds are labelled A, B, C, D, E, F, G and H, and their displayed formulae are shown.
May/June 2015
The general expression for a carboxylic acid is $\text{C}_n\text{H}_{2n+1}\text{COOH}$. G is a carboxylic acid with relative formula mass $88$.
May/June 2015
Ethanol, $\text{C}_2\text{H}_6\text{O}$, was allowed to react with propanoic acid, $\text{C}_3\text{H}_6\text{O}_2$, with concentrated sulfuric acid present. Which statement about the organic product from this reaction is correct?
May/June 2016
How many of the structures displayed are unsaturated hydrocarbon molecules?
May/June 2016
Esters serve as food flavourings and as solvents.
May/June 2016
Following which conversion does the product have more carbon atoms than the reactant?
May/June 2017
Molecules 1-4 are straight-chain hydrocarbons. 1 $\text{C}_{10}\text{H}_{22}$ 2 $\text{C}_{10}\text{H}_{20}$ 3 $\text{C}_{9}\text{H}_{20}$ 4 $\text{C}_{8}\text{H}_{16}$ Which row correctly classifies these hydrocarbons as alkanes or alkenes?
May/June 2017
The structure of Ester A is shown here.
May/June 2018
State the empirical formula of ethanoic acid.
May/June 2019
The structures of cyclobutanol and butanoic acid are displayed.
May/June 2019
A student has three colourless liquids, A, B and C. She is told that the liquids are hexene, ethanol and ethanoic acid. Her task is to identify A, B and C.
May/June 2019
Which circled structure indicates only the functional group of a carboxylic acid?
May/June 2021
Select your answers from the compounds below. Each compound may be used once, more than once, or not at all. The compounds are displayed as A, B, C, D, E, F and G with their structural formulae.
May/June 2021
Use the compounds listed below to answer the questions. They are marked A, B, C, D, E, F, G and H, and their displayed formulae are given. Each compound may be chosen once, more than once, or not chosen at all.
May/June 2021
The displayed diagram shows the structure of ethyl propenoate.
May/June 2021
Which compounds are shown by the molecular formula $\text{C}_3\text{H}_6\text{O}_2$?
May/June 2022
A student is given three colourless organic liquids, W, X and Y. Of these, one is an alkene, one is an alcohol and one is a carboxylic acid, but the student does not know the identity of each liquid.
May/June 2022
The displayed diagrams show the structures of three compounds, W, X and Y. Which of the following statements about these three compounds are correct? 1 W and Y are both alcohols, while X is a carboxylic acid. 2 W, X and Y all have the same molecular formula. 3 W and Y are structural isomers of each other.
May/June 2023
When calcium carbide, $\text{CaC}_2$, comes into contact with water, it produces the flammable gas ethyne, $\text{C}_2\text{H}_2$, together with calcium hydroxide.
May/June 2024
Fig. 8.1 presents the displayed formula for compound A.
May/June 2025
The diagram illustrates the structure of an organic acid. Which row is correct?
Oct/Nov 2015
The structures of three hydrocarbons belonging to the same homologous series are shown (W, X and Y). Which statement is correct?
Oct/Nov 2015
Proteins and nylon each contain the same amide linkages. Which atom arrangement shows an amide linkage?
Oct/Nov 2015
Plants are composed of many different kinds of carbon compounds.
Oct/Nov 2015
The diagram presents the structures of two hydrocarbons, X and Y. Two students give the following statements. Student 1: Hydrocarbon X is an isomer of Y. Student 2: Hydrocarbon X is unsaturated whereas Y is saturated. Which students are correct?
Oct/Nov 2016
Which claim about a compound’s isomers is always true?
Oct/Nov 2016
When one mole of an organic compound, $Q$, undergoes complete combustion in oxygen, exactly three moles of water are formed. Which compound is $Q$?
Oct/Nov 2017
When one mole of the organic compound Q is completely burnt in oxygen, exactly three moles of water are formed. Which compound is Q?
Oct/Nov 2017
Lavandulol occurs in lavender plants.
Oct/Nov 2017
The diagram shows the structural formula of an organic compound. Which statement concerning this compound is correct?
Oct/Nov 2018
Which functional group is present in alcohols?
Oct/Nov 2018
An ester is produced when a carboxylic acid reacts with an alcohol. In what way does the number of carbon, hydrogen and oxygen atoms in an ester compare with the combined total of these atoms in the carboxylic acid and alcohol used to make it?
Oct/Nov 2018
Tartaric acid and succinic acid are colourless organic acids, and their structures are displayed below.
Oct/Nov 2018
Which of the following statements are true about homologous series?
Oct/Nov 2019
Of the structural isomers with the formula $\text{C}_4\text{H}_{10}\text{O}$, how many are alcohols?
Oct/Nov 2019
Which compound could be suitable for flavouring a soft drink?
Oct/Nov 2019
Which compound could act as a flavouring agent in a non-alcoholic fruit drink?
Oct/Nov 2021
The two isomers are shown below. Which statements about these isomers are true?
Oct/Nov 2021
Which structural formula shows an alcohol?
Oct/Nov 2021
A covalent compound P has the empirical formula $\text{CH}_2\text{O}$. Which structure is P represented by?
Oct/Nov 2021
Some medicines include the magnesium salt of a fatty acid. Fatty acids are part of the homologous series of carboxylic acids and have one carboxylic acid group. State the carboxylic acid functional group and how many moles of a fatty acid react with 1 mole of magnesium?
Oct/Nov 2022
Which compounds are members of the same homologous series?
Oct/Nov 2023
The diagrams illustrate four possible structures of $\text{C}_4\text{H}_8$. Which of these structures show the same molecule?
Oct/Nov 2023
Compound X turns acidified aqueous potassium manganate(VII) colourless. Compound X has the empirical formula $\text{C}_2\text{H}_5\text{O}$. Several possible structures for X are shown. Which of these structures could be correct for compound X?
Oct/Nov 2023
Which of the following statements about organic compounds is correct?
Oct/Nov 2023
A chlorine atom may substitute for a hydrogen atom in a butane molecule, $\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3$, producing chlorobutane. How many distinct structural isomers of chlorobutane are possible?
Oct/Nov 2023
Which compound is neither an alkane, alkene, alcohol nor carboxylic acid?
Oct/Nov 2024
How many distinct unbranched esters have the molecular formula $\text{C}_4\text{H}_8\text{O}_2$?
Oct/Nov 2024
Which of these statements about hydrocarbons is correct?
Oct/Nov 2024
What number of structural isomers exist for the molecular formula $\mathrm{C_4H_9Cl}$?
Oct/Nov 2025
Which pair of compounds combine to produce $\mathrm{CH}_3\mathrm{CH}_2\mathrm{COOCH}_3$?
Oct/Nov 2025
Use the compounds listed below to answer the questions. compound A: CH3OH compound B: CH3CH2OH compound C: cyclopropane ring (three CH2 groups) compound D: CH3CH=CH2 compound E: CH3CH2COOCH3 compound F: CH3CH2CH2CH2COOH compound G: CH3CH=CHCOOCH3 You may use each compound once, more than once, or not use it at all.
Oct/Nov 2025
Use the compounds listed below to answer the questions. Compound A: CH3OH. Compound B: HCOOH. Compound C: CH3CH2OH. Compound D: CH3COOCH3. Compound E: cyclobutane (ring of four CH2 groups). Compound F: CH3CH2CH2CH3. Compound G: CH3CH2CH=CH2. Compound H: CH3CH2CH2COOH. Each compound may be selected once, more than once, or not selected at all.
Oct/Nov 2025