1
Which statement is wrong ?
- Bond energy of F2 > Cl2
- Electronegativity of F > Cl
- F is more oxidising than Cl
- Electron affinity of Cl > F
Answer
(1) Bond energy of F2 > Cl2
Solution
As per NCERT, bond dissociation enthalpy of F2 (158.8 kJ mol-1) is smaller than that of Cl2 (242.6 kJ mol-1).
∵ F is very small, so the lone pairs on the two F atoms repel each other strongly and weaken the F–F bond.
⇒ Statement (1) is wrong.
(2) F is the most electronegative element — correct.
(3) F2 is the strongest oxidising agent (low bond enthalpy, high hydration enthalpy) — correct.
(4) Electron gain enthalpy of Cl is more negative than that of F (small size of F causes electron–electron repulsion) — correct.
Answer: (1)
AIPMT 2000