Chemistry 9701 · AS & A Level
An introduction to AS Level organic chemistry
59 practice questions on An introduction to AS Level organic chemistry, with worked solutions and instant marking.
Some people who use statin drugs to lower their blood cholesterol also take ‘coenzyme $\text{Q}_{10}$’. The diagram shows a simplified structure of one form of this coenzyme. Which row correctly identifies this structure?
Feb/March 2016
These compounds were identified as components in a petrol sample. G: $\text{CH}_3(\text{CH}_2)_2\text{CH}_3$, H: $(\text{CH}_3)_3\text{CCH}_2\text{CH}(\text{CH}_3)_2$, J: a displayed alcohol structure.
Feb/March 2016
Which radical is most likely to be produced when one covalent bond in bromochloromethane, $\text{CH}_2\text{BrCl}$, undergoes homolytic fission?
Feb/March 2017
Which two compounds are a pair of functional group isomers?
Feb/March 2020
P, Q and R compounds have been detected in the atmosphere of one of Saturn’s moons.
Feb/March 2021
When answering this question, you should take both structural isomerism and stereoisomerism into account. P has the molecular formula $\text{C}_5\text{H}_{10}\text{O}$. P gives an orange precipitate with 2,4-dinitrophenylhydrazine (2,4-DNPH reagent). How many isomeric structures are possible for P?
Feb/March 2023
Compound S is a food flavouring. One possible route for the synthesis of S is shown in Fig. 4.1.
Feb/March 2024
The molecular structure of the hormone histamine is shown. Which row gives the bond angles $x$, $y$ and $z$ in histamine arranged correctly from the smallest to the largest?
Feb/March 2025
Which compound displays both cis-trans and optical isomerism?
May/June 2010
The diagram illustrates the molecular structure of the naturally occurring molecule cholesterol. Student X said that all seventeen carbon atoms in the four rings are in one plane. Student Y said that this molecule shows $cis$-$trans$ isomerism about the $\text{C} = \text{C}$ double bond. Which students are correct?
May/June 2011
The diagram illustrates the structure of the naturally occurring molecule cholesterol. Student X stated that all seventeen carbon atoms in the four rings are situated in one plane. Student Y stated that this molecule shows $cis$-$trans$ isomerism around the $\text{C}=\text{C}$ double bond. Which of the students are correct?
May/June 2011
The compound illustrated is a hormone made during pregnancy that inhibits ovulation. Which reagents would produce positive tests with this compound?
May/June 2012
Methanol, $\text{CH}_3\text{OH}$, is viewed as a potential substitute for fossil fuels, especially in vehicles. It may be made from fossil fuels or agricultural waste. It can also be synthesised from carbon dioxide and hydrogen.
May/June 2012
A liquid X is known to be either a single organic compound or a mixture of organic compounds. When X is treated with sodium, hydrogen gas is released. When X is treated with 2,4-dinitrophenylhydrazine reagent, orange crystals are formed. Which deductions about X can definitely be made?
May/June 2013
Aspartame is commonly used as a sweetening agent in ‘diet’ soft drinks. Aspartame is a chiral molecule. (No chiral carbon atoms are present in $\text{C}_6\text{H}_5$.) How many chiral carbon atoms does one molecule of aspartame contain?
May/June 2015
What is the proper name for the molecule represented by the skeletal formula shown?
May/June 2016
Structural isomerism and stereoisomerism must be taken into account when answering this question. Which formula identifies only one substance?
May/June 2017
The diagram depicts the skeletal formula of compound Y. Determine the empirical formula of Y.
May/June 2019
The skeletal formula for compound X appears below. Which row is the correct one?
May/June 2020
Which row correctly identifies the mechanism type for each of these two reactions? C$_2$H$_5$Br + KCN CH$_3$COCH$_3$ + HCN
May/June 2020
Which statement concerning compound T and compound U is correct?
May/June 2020
Which of the following pairs are structural isomers of one another?
May/June 2020
(a) Here is a list of species that are able to react with organic compounds. $\text{CN}^-$, $\text{HCl}$, $\text{Cl}^-$, $\text{H}_2\text{O}$, $\text{CO}_3^{2-}$
May/June 2020
In reaction A, sucrose, $\text{C}_{12}\text{H}_{22}\text{O}_{11}$, combines with water to give glucose and fructose: $\text{C}_{12}\text{H}_{22}\text{O}_{11} + \text{H}_2\text{O} \rightarrow$ glucose $+$ fructose.
May/June 2020
Which compound might exhibit both cis-trans isomerism and optical isomerism?
May/June 2021
Which reaction mechanism is correct for the formation of $\text{C}_2\text{H}_5\text{CH(OH)(CN)}$?
May/June 2021
The displayed skeletal structures represent two organic compounds. Which reagents could be used to tell these two compounds apart?
May/June 2022
Fructose is a sugar containing more than one chiral centre. The fructose molecule is shown below, with X, Y and Z marking three carbon atoms. Which carbon atoms are chiral centres?
May/June 2025
The arrangement of a molecule present in food is shown. Four statements about the molecule are given. Which two of the statements are correct?
May/June 2025
When answering this question, both structural isomerism and stereoisomerism need to be taken into account. How many isomeric esters of methanoic acid can be formed with the molecular formula $\text{C}_5\text{H}_{10}\text{O}_2$?
May/June 2025
Which of the compounds shown contain chiral carbon atoms?
Oct/Nov 2010
The table lists the physical properties of three compounds. What could P, Q and R be?
Oct/Nov 2011
When compound X undergoes complete combustion, the only products formed are carbon dioxide and water. X gives steamy fumes with $\text{PCl}_5$. X shows no visible reaction with 2,4-dinitrophenylhydrazine reagent. What can be deduced with certainty from this information?
Oct/Nov 2012
Carbon dioxide, $\text{CO}_2$, contributes about $0.040\%$ to Earth’s atmosphere. It comes from animal respiration and from the burning of fossil fuels. During animal respiration, oxygen reacts with a carbohydrate such as glucose to produce water, carbon dioxide and energy. A typical person’s daily food intake may be treated as the same as $1.20\,\text{kg}$ of glucose, $\text{C}_6\text{H}_{12}\text{O}_6$. All numerical answers in this question should be given to three significant figures.
Oct/Nov 2012
The molecular formula $\text{C}_4\text{H}_8\text{O}$ may correspond to several compounds with different functional groups, and these compounds can display different kinds of isomerism. Compounds H, J and K each have the molecular formula $\text{C}_4\text{H}_8\text{O}$. In each molecule of H, J and K, the carbon chain is straight and the molecule is not cyclic, and no oxygen atom is bonded to any carbon atom that is involved in $\pi$ bonding. When compound H is reacted with sodium metal, a colourless flammable gas is formed. Both J and K produce an orange-red precipitate on reaction with 2,4-dinitrophenylhydrazine reagent, but only K reacts with Fehling’s solution.
Oct/Nov 2012
Which compound shows stereoisomerism?
Oct/Nov 2013
During which reaction is the organic compound oxidised?
Oct/Nov 2013
Which option shows the skeletal formula for 2-bromopentan-4-ol?
Oct/Nov 2013
The structural formulae of two compounds are shown below. Which of the following statements about these compounds are correct?
Oct/Nov 2013
Perspex is made using methyl methylpropenoate as the monomer. Which diagram shows methyl methylpropenoate correctly?
Oct/Nov 2014
Each molecule of compound Q has three double bonds. $\text{CH}_2{=}\text{CH}{-}\text{CH}_2{-}\text{C}(=\text{O}){-}\text{CH}_2{-}\text{C}(=\text{O}){-}\text{OH}$ Using hot, concentrated acidified $\text{KMnO}_4$, which bond, X or Y, is broken, and how many lone pairs of electrons are there in one molecule of Q?
Oct/Nov 2015
The structural formula for compound $Q$ is given. How many stereoisomers can this structural formula have?
Oct/Nov 2017
A great many, though not every, organic reaction has to be heated before it takes place. Which reaction takes place rapidly at room temperature, $20^{\circ}\text{C}$?
Oct/Nov 2017
Which compound does not show stereoisomerism?
Oct/Nov 2017
Which organic reaction counts as an example of nucleophilic substitution?
Oct/Nov 2017
A new jet fuel has been made and it is a mixture containing different structural isomers of compound Q. The skeletal formula for Q is shown. Which skeletal formula shows a structural isomer of Q?
Oct/Nov 2018
cis-hex-3-enal is the compound that produces the characteristic smell of cut grass. Which reagents can react with cis-hex-3-enal?
Oct/Nov 2018
An organic compound X is treated with hot, concentrated acidified potassium manganate(VII) solution and produces only one carbon-containing product. What could X be?
Oct/Nov 2019
The structure of compound R is shown. Which of the following statements about compound R are correct?
Oct/Nov 2020
The skeletal structure of compound X is shown. What is the molecular formula of compound X?
Oct/Nov 2020
The structure of compound R is shown. Which statements concerning compound R are correct?
Oct/Nov 2020
In one molecule of 2,2,4,5-tetramethylhexan-3-ol, how many chiral carbon atoms are present?
Oct/Nov 2022
The structure of tartaric acid is illustrated. Which of the following statements about tartaric acid are correct?
Oct/Nov 2022
The table presents a student’s predictions about how three compounds will react. Which rows contain the correct predictions?
Oct/Nov 2022
In one molecule of 2,2,4,5-tetramethylhexan-3-ol, how many chiral carbon atoms are present?
Oct/Nov 2022
Artemisinin is a potent anti-malarial medicine. How many chiral centres are present in each molecule of artemisinin?
Oct/Nov 2023
Compound X occurs in the cell walls of certain bacteria. Its structural formula is given. compound X $\text{CH}_3(\text{CH}_2)_{17}\text{CH}=\text{CH}(\text{CH}_2)_{17}\text{CH(OH)CH(CH}_3)\text{CO}_2\text{H}$ How many stereoisomers can exist for this structural formula?
Oct/Nov 2024
Which statement applies to all nucleophiles?
Oct/Nov 2024
Geraniol and nerol are isomers of one another. What kind of isomerism is shown here?
Oct/Nov 2024