Question detail
What makes alkenes unsaturated?
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. They contain a triple bond.
- B. They contain two fewer hydrogen atoms than the corresponding alkane.
- C. They are only made of carbon atoms.
- D. They have no double bonds.
Answer
The correct option is They contain two fewer hydrogen atoms than the corresponding alkane..
Explanation
The correct option is They contain two fewer hydrogen atoms than the corresponding alkane.. They contain two fewer hydrogen atoms than the corresponding alkane. is correct because it directly supports the approved learning objective to recall the first four members of the homologous series of alkenes as ethene, propene, butene and pentene. This belongs to Structure and formulae of alkenes 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
Naming Alkenes
Students often confuse the names of the first four alkenes, mixing them up or omitting one.
Memorize the names in order: ethene, propene, butene, and pentene. Use flashcards or mnemonic devices to help remember.
Related flashcards
Flashcard 1 of 5
Related practice questions
Question 1 of 5
Choose an answer, get feedback, then move sideways through the set.