Answer: The carbon bearing more hydrogen atoms.
- A The carbon bearing more hydrogen atoms
- B The carbon bearing fewer hydrogen atoms
- C The more substituted carbon atom
- D The carbon further from the double bond
Correct answer: A. The carbon bearing more hydrogen atoms
Explanation: H adds to the carbon already having more hydrogens so that the more stable (secondary) carbocation forms, placing Br on the other carbon.
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.