The C–X bond enthalpies follow the order:
AC–F < C–Cl < C–Br < C–I
BAll bond enthalpies are equal
CC–I > C–Br > C–F > C–Cl
DC–F > C–Cl > C–Br > C–I (decreases down the group)
Answer & Solution
Correct answer: D. C–F > C–Cl > C–Br > C–I (decreases down the group)
**Bond enthalpy decreases down the group**: C–F (452) > C–Cl (351) > C–Br (293) > C–I (234 kJ/mol). Reason: bond length **increases** down the group as halogen size grows → weaker bond. C–I is the weakest, so iodide is the best leaving group.
Related questions
With which two hydrogen halides is the peroxide effect not observed?Addition anti to Markovnikov rule is known as the peroxide or:Who framed the rule for adding HBr to unsymmetrical alkenes, in 1869?An intermediate conformation between eclipsed and staggered is called:Eclipsed and staggered conformations are represented by Newman and:Across all conformations, what stays the same?How many conformations can an alkane have by rotation about single bonds?Spatial arrangements interconverted by rotation about a single bond are called: