Question detail
Which of the following is the first member of the carboxylic acids homologous series?
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
MCQ
Type
practice
Style
Topic
Reactions of alkenes and alcohols (chemistry only)
Question
- A. Ethanoic acid
- B. Butanoic acid
- C. Methanoic acid
- D. Propanoic acid
Answer
The correct option is Methanoic acid.
Explanation
The correct option is Methanoic acid. Methanoic acid is correct because it directly supports the approved learning objective to explain why carboxylic acids are weak acids in terms of ionisation and pH. (HT only). This belongs to Carboxylic acids within Reactions of alkenes and alcohols (chemistry only), so the answer must use the correct organic chemistry context. The other options are incorrect when they confuse the organic family, formula type, reaction condition, product, or property being tested. Keep molecular formula, structural formula, displayed formula, and general formula distinct. Do not confuse alkanes with alkenes, saturated with unsaturated, cracking with combustion, polymers with monomers, or hydrocarbons with oxygen-containing alcohols and carboxylic acids. When formulae are used, preserve the stored notation exactly and explain the GCSE chemistry idea in words rather than using unsupported displayed-formula diagrams.
Common mistake
Weak acid misconception
Students think carboxylic acids are strong acids because they contain an –OH group, just like alcohols.
Explain that the –COOH group can donate a proton, but the resulting –COO⁻ conjugate base is resonance‑stabilised, making the acid weak; contrast with alcohols, which do not ionise appreciably.
Related flashcards
Flashcard 1 of 5
Related practice questions
Question 1 of 5
Choose an answer, get feedback, then move sideways through the set.