A chemist investigates the effect of compound X on the length of condensation polymer chains.
Each polymer-forming monomer has two functional groups. Compound X has one functional group that can react with a functional group at the end of a growing polymer chain.
All other conditions are kept the same.
| Amount of compound X in the reaction mixture in mmol | Mean number of repeating units per polymer molecule |
|---|---|
| 0.00 | 940 |
| 0.30 | 420 |
| 0.60 | 230 |
| 0.90 | 150 |
Explain the pattern shown in the results.
The chemist repeats the experiment using 1.20 mmol of compound X.
Predict how the mean number of repeating units per polymer molecule would compare with 150.
94 exam-style questions on AQA GCSE Chemistry 7.3 Synthetic and naturally occurring polymers, covering 7.3.1 Addition polymerisation, 7.3.2 Condensation polymerisation, 7.3.3 Amino acids, and 7.3.4 DNA (deoxyribonucleic acid) and other naturally occurring polymers. Each one has a worked solution and a mark scheme showing where the marks go.