Question 1
Which two reactants form ethyl propanoate?
Need a hint for Question 1?
Split an ester at C(=O)–O. Identify the acid-derived and alcohol-derived portions.
Check Question 1
Ethanol and propanoic acid.
STUDENT SPACE · TOPIC 6
Carboxylic acids and esters
Explain acid reactions, ethanol oxidation and ester formation.
The essentials
- 2CH₃COOH + Mg → (CH₃COO)₂Mg + H₂. CH₃COOH + NaOH → CH₃COONa + H₂O.
- C₂H₅OH + 2[O] → CH₃COOH + H₂O. Acidified aqueous potassium manganate(VII) oxidises ethanol.
- Carboxylic acid + alcohol ⇌ ester + water, using an acid catalyst.
- The alcohol gives the alkyl name. The acid gives the name ending in -oate.
Key vocabulary
| English | Chinese |
|---|---|
| carboxylic acid | 羧酸 |
| ester | 酯 |
| oxidation | 氧化 |
Quick practice
Try each question before opening its hint or answer. Use paper for calculations and diagrams.
Question 2
Write the equation for ethanoic acid reacting with sodium carbonate.
Need a hint for Question 2?
A carbonate needs enough acid to form a salt, water and CO₂.
Check Question 2
2CH₃COOH + Na₂CO₃ → 2CH₃COONa + H₂O + CO₂.
Question 3
Name and draw the displayed ester from methanol and butanoic acid.
Need a hint for Question 3?
The alcohol supplies the alkyl part; the acid supplies the carboxylate part.
Check Question 3
Methyl butanoate: CH₃CH₂CH₂COOCH₃. Display C=O and every other bond.
Use Lesson 6 in your worksheet for written practice. Your teacher will discuss those answers in class.