This question is about straight-chain carboxylic acids. Table 1 shows information about some of these carboxylic acids.
| Number of carbon atoms in carboxylic acid | Boiling point in ∘C^{\circ}\text{C}∘C |
|---|---|
| 3 | 141 |
| 4 | 164 |
| 5 | YYY |
| 6 | 205 |
| 7 | 223 |
| 8 | 239 |
Predict the boiling point YYY of the carboxylic acid with five carbon atoms.
A student wants to plot this data on a grid where the vertical scale for boiling point starts at 150 ∘C150\,^{\circ}\text{C}150∘C. Describe why this grid is not suitable to show the boiling point of the carboxylic acid with three carbon atoms.
Determine the physical state of the carboxylic acid with three carbon atoms at 150 ∘C150\,^{\circ}\text{C}150∘C. Use Table 1 to support your answer.
The carboxylic acid with eight carbon atoms is octanoic acid. Complete the molecular formula:
C8H‾O2 \text{C}_8\text{H}_{\underline{\quad}}\text{O}_2 C8HO2Octanoic acid condenses lower down in a fractionating column during fractional distillation than the other carboxylic acids in Table 1. Explain why. You should refer to the temperature gradient in the fractionating column.
12 exam-style questions on AQA GCSE Chemistry 7.2 Reactions of alkenes and alcohols, covering 7.2.1 Structure and formulae of alkenes, 7.2.2 Reactions of alkenes, 7.2.3 Alcohols, and 7.2.4 Carboxylic acids. Each one has a worked solution and a mark scheme showing where the marks go.