Structural isomerism and E-Z isomerismAQA A-Level Chemistry: Flashcards

What these 14 flashcards ask

Define the term structural isomer.
What are chain isomers?
What are position isomers?
What are functional group isomers?
How many structural isomers does C₅H₁₂ have?
Define the term stereoisomer.
Why does E-Z isomerism occur?
What two conditions are needed for E-Z isomerism?
What does CIP stand for?
How do you decide the priority of two groups on a C=C carbon?
What is a Z isomer?
What is an E isomer?
Which has higher CIP priority, CH₂CH₃ or CH₃?
Why can butan-1-ol and ethoxyethane react differently?

Exam questions on Structural isomerism and E-Z isomerism

A refinery chemist is analysing the C₅ fraction of a petroleum sample. The fraction is a mixture of alkanes with the molecular formula C₅H₁₂, which are blended into petrol.
Explain why pentane and 2-methylbutane are structural isomers of each other.2 marks
A student is comparing four alkenes: but-1-ene, CH₂=CHCH₂CH₃; but-2-ene, CH₃CH=CHCH₃; 2-methylpropene, (CH₃)₂C=CH₂; and propene, CH₃CH=CH₂.
In one isomer of but-2-ene, both methyl groups are on the same side of the double bond. Use the CIP priority rules to explain why this isomer is the Z isomer.2 marks
But-1-ene, CH₂=CHCH₂CH₃, is an alkene used to make polymers. Its molecular formula, C₄H₈, is shared by several other compounds.
Explain why but-1-ene does not show E-Z isomerism but but-2-ene does.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).