AQA · GCSE · Chemistry
Course version: 8462 · Version from Sept 2018
The simplest polymers are produced from two different monomers with two of…
Full specification wording
Condensation polymerisation (HT only): The simplest polymers are produced from two different monomers with two of the same functional groups on each monomer.
The simplest condensation polymers form when two different monomers each carry two identical functional groups.
Checked against the AQA 8462 specification (opens in a new tab) on .
- Point 3 of 4
- 3 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
The simplest condensation polymers form when two different monomers each carry two identical functional groups. One monomer might be a diol with two alcohol groups, and the other a dicarboxylic acid with two carboxylic acid groups. Because each monomer has two reactive groups, it can bond at both ends, allowing a long chain to build up. If a monomer had only one functional group, chain growth would stop after one link. Using two different monomers with matching pairs of groups gives a regular alternating pattern in the polymer chain. This is why the simplest polyesters are made from pairs such as a diol and a dicarboxylic acid, reacting to form ester links and water.
What earns the marks
- Two different monomers are used in the simplest condensation polymers.
- Each monomer has two of the same functional group.
- A diol has two alcohol groups and a dicarboxylic acid has two carboxylic acid groups.
- Two functional groups per monomer allow chain growth in two directions.
- A monomer with only one functional group would terminate chain growth.
- The resulting polymer has an alternating pattern of the two monomer units.
Common mistakes and how to put them right
Thinking the two functional groups on a monomer must be different.
Put it right by noting they are the same on each monomer in the simplest case.
Believing one functional group per monomer is enough.
Put it right by explaining that chain growth needs two reactive sites.
Assuming the two monomers must be identical.
Put it right by stating that two different monomers are used.
Exam tips
- Name the functional groups present on each monomer before predicting the polymer.
- Check that each monomer has two reactive sites before describing chain growth.
- Use 'diol' and 'dicarboxylic acid' accurately when giving examples.
Try the lesson
The start of the Condensation polymerisation (HT only): The simplest polymers are produced from two different monomers with two of the same functional groups on each monomer. lesson, made from checked teaching notes for this specification point.
Have a go first
In the simplest condensation polymerisation, how many functional groups of the same type are present on each monomer molecule?
Listen
The simplest condensation polymers form when two different monomers each carry two identical functional groups. One monomer might be a diol with two alcohol groups, and the other a dicarboxylic acid with two carboxylic acid groups. Because each monomer has two reactive groups, it can bond at both ends, allowing a long chain to build up. If a monomer had only one functional group, chain growth would stop after one link. Using two different monomers with matching pairs of groups gives a regular alternating pattern in the polymer chain. This is why the simplest polyesters are made from pairs such as a diol and a dicarboxylic acid, reacting to form ester links and water. A strong answer earns marks for these points. Two different monomers are used in the simplest condensation polymers. Each monomer has two of the same functional group. A diol has two alcohol groups and a dicarboxylic acid has two carboxylic acid groups. Two functional groups per monomer allow chain growth in two directions. A common slip: Thinking the two functional groups on a monomer must be different. Instead, noting they are the same on each monomer in the simplest case. Exam tip: Name the functional groups present on each monomer before predicting the polymer.
Key words
Say what each word means before you turn the card.
Monomer structure
Try answering aloud or in your head before turning the card.
Chain growth
Try answering aloud or in your head before turning the card.
Polymer architecture
Try answering aloud or in your head before turning the card.
See every definition
- Monomer structure
- Each monomer has two of the same functional group, such as a diol with two alcohol groups or a dicarboxylic acid with two carboxylic acid groups.
- Chain growth
- Two functional groups per monomer allow chain growth in two directions, while a monomer with only one functional group would terminate chain growth.
- Polymer architecture
- Using two different monomers with matching pairs of groups gives a regular alternating pattern in the polymer chain.
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Condensation polymerisation (HT only): The simplest polymers are produced from two different monomers with two of the same functional groups on each monomer.
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge