Question

Identify false statement from the following about fluorine.

• A. It is highly electronegative element.
• B. It exhibits only -1 oxidation state.
• C. It has high bond dissociation enthalpy among all halogens.
• D. It form only one oxoacid.

Hint:

Bond strength order for halogens: $\text{Cl}_2 > \text{Br}_2 > \text{F}_2 > \text{I}_2$. Fluorine is weak because its lone pairs are cramped and repel each other.

Answer 1

The Correct Option is C

Step 1: Concept
Fluorine is the first element of the halogen group and shows several anomalous properties due to its small size and high electronegativity.

Step 2: Meaning
Bond dissociation enthalpy is the energy required to break one mole of bonds.

Step 3: Analysis
(A) is true (most electronegative). (B) is true (no d-orbitals). (D) is true ($\text{HOF}$). However, (C) is false. The $\text{F—F}$ bond dissociation enthalpy is lower than $\text{Cl—Cl}$ and $\text{Br—Br}$ because the small size of fluorine leads to large electron-electron repulsion between lone pairs of the two atoms.

Step 4: Conclusion
The statement that it has the "high" bond dissociation enthalpy is incorrect; it is actually surprisingly low. Final Answer: (C)