Question

C – Cl bond is stronger than C – I bond, because:
a.) C – Cl bond is more ionic than C – I
b.) C – Cl bond is polar covalent bond
c.) C – Cl bond is more covalent than C – I
d.) C – Cl bond length is longer than C – I

Answer 1

Hint: Bond energy is defined as the amount of energy required to break apart a mole of molecules into its component atoms. It is a measure of the strength of a chemical bond. Bond energy is also known as bond enthalpy or simply as bond strength.

Complete answer:
Stronger bonds are more difficult to break, making them less reactive. In addition, the reactivity can also be determined by the stability of the corresponding anion formed in solution.
Let us see the bond reactivity,
When chlorine leaves as chloride in the reaction, it is not so stable compared to iodine. Because there are no resonance forms and inductive stabilizing effects on these individual atoms, the atoms must utilize their own inherent abilities to stabilize themselves. Iodine has the greatest surface, while chlorine has the least surface area, so it is much more difficult to stabilize.

Now, considering the question:
The average bond energy of C – Cl is 382kj/mol while that of C – I bond is 240kj/mol. C – Cl bond is more ionic than C – I bond because of the greater difference in the electronegativities of C and Cl as compared to that of carbon and iodine. Therefore, C – Cl bond is stronger than the C – I bond. So, the correct answer is “Option A”.

Note: The strength of a bond between two atoms increases as the number of electron pairs in the bond increases. Generally, as the bond strength increases, the bond length decreases.