AQA A Level Chemistry - Isomers

What is a structural isomer?

• Same molecular formula but different structural formula.

• Different functional groups.

• Different bonds in the structure.

• Change in the position of the functional group.

Name this isomer of heptane

• 5-methyl-heptane

• 2-methyl-hexane

• 2-methyl-heptane

• 5-methyl-hexane

How many isomers are there of pentene?

• 7

• 6

• 5

• 2

What is positional isomerism?

• Swap the position of two functional groups.

• Chain has the same molecular formula but a different chain length.

• Functional group is different.

• Same functional group and a different position.

What is a chain isomer?

• It is arranged in the shape of a circle.

• The chain is of a different length.

• The functional groups are different.

What is E-Z isomerism?

• An E isomer is where molecules with atoms or groups on opposite sides.

• E-Z isomerism is another way of naming structural isomers.

• A Z isomer is where molecules with atom or groups are on the same side.

• An example of chain isomerism.

What is the molecular formula of 1,2-dichloroethene?

• C₂H₄Cl₂

• C₂H₄Cl₁

• C₂H₂Cl₂

• C₂H₂Cl₁

What are the two correct isomers of hexane?

• 2-methylpentane

• 2-methylpropane

• 2,2-dimethylbutane

• 1-methylethene

What is the shortest chain-length alkane to have structural isomer?

• Ethane

• Butane

• Hexane

• Pentane

Which one of these are types of isomerism?

• Structural Isomerism

• Positional Isomerism

• Molecular Isomerism

• E-Z Isomerism