Answer: Two molecules of ethanal (acetaldehyde).
- A One ethanal and one propanone
- B Two molecules of methanal (formaldehyde)
- C Two molecules of ethanal (acetaldehyde)
- D Two molecules of propanone (acetone)
Correct answer: C. Two molecules of ethanal (acetaldehyde)
Explanation: CH3CH=CHCH3 is cleaved at the double bond; each carbon carries one H and one CH3, giving two molecules of ethanal.
Going from a single to a triple bond between carbons increases the s-character of hybridisation (sp³→sp²→sp), shortening the bond and locking the geometry, while increasing π-bond reactivity (alkenes and alkynes readily undergo addition reactions that alkanes don't).
Concept context
The simplest organic compounds made only of carbon and hydrogen. Covers alkanes, alkenes, alkynes, and aromatic compounds like benzene. Learn preparation methods, key reactions, and physical properties.