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WorksheetsH2 CHEM (9476) - 7B - Isomerism Quiz
Total questions: 10
Worksheet time: 10mins
Propan-1-ol (CH3CH2CH2OH) and propan-2-ol (CH3CH(OH)CH3) share the molecular formula . Which statement best describes their relationship?
They are chain isomers because the arrangement of carbon atoms is different.
They are positional isomers because the hydroxyl functional group is attached to a different carbon atom in the chain.
They are stereoisomers because they have a different spatial arrangement of atoms.
They are functional group isomers because one is a primary alcohol and the other is a secondary alcohol.
Which of the following alkenes can exhibit cis-trans isomerism?
Propene
Pent-1-ene
Pent-2-ene
2-Methylbut-2-ene
The existence of cis-trans isomerism in alkenes arises from a specific feature of the carbon-carbon double bond. What is this feature?
The planar geometry resulting from sp2 hybridisation.
The restricted rotation caused by the presence of a pi (π) bond.
The electrostatic repulsion between the substituent groups.
The high bond energy of the sigma (σ) bond.
A molecule is described as chiral. What property must this molecule possess?
It must be non-superimposable on its mirror image.
It must have an internal plane of symmetry.
It must contain at least one double bond.
It must contain a carbon atom bonded to four other carbon atoms.
How do a pair of enantiomers differ from one another?
They rotate plane-polarised light in opposite directions.
They have different molecular formulas and connectivity.
They react at different rates with achiral reagents.
They have different boiling points and melting points.
A 50:50 mixture of two enantiomers, known as a racemic mixture, is optically inactive. What is the reason for this?
The chiral molecules pair up to form an achiral unit.
The clockwise rotation of light by one enantiomer is exactly cancelled by the anti-clockwise rotation of the other.
The presence of both enantiomers introduces a plane of symmetry into the solution.
In a 50:50 mixture, all the molecules become achiral meso compounds.
The molecule meso-tartaric acid has two chiral centers but is achiral and optically inactive. What structural feature accounts for this?
The molecule is perfectly symmetrical and therefore cannot have chiral centers.
The two chiral centers cancel each other out due to an internal plane of symmetry.
It rapidly interconverts with its enantiomer, resulting in no net optical activity.
It exists as a racemic mixture of itself.
The drug thalidomide was sold as a racemic mixture, where one enantiomer was an effective treatment for morning sickness, but the other caused severe birth defects. This illustrates that enantiomers can have different biological properties. Why does this occur?
One enantiomer is much more water-soluble, affecting its distribution in the body.
Biological systems, such as enzyme active sites and receptors, are themselves chiral.
The two enantiomers have different functional groups, leading to different reactions in the body.
One enantiomer is significantly less stable and decomposes into a toxic substance.
What is the maximum number of stereoisomers possible for the molecule 4-bromopent-2-ene, CH3CH=CHCHBrCH3?
4
8
3
2
Which of the following molecules is chiral?
2,2-dichloropropane
1,3-dichloropropane
cis-1,2-dichlorocyclopropane
trans-1,2-dichlorocyclopropane
