Chemistry · Chemical Bonding
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Molecule are having the highest bond energy (experimentally) is:
- A
HCl
- B
HF
- C
HBr
- D
HI
The correct option is B as the decreasing order of bond dissociation energy is HF > HCl > HBr > HI. There is a large difference between electronegativity of H and F, so the bond is stronger. As we go down the group, the difference between electronegativity decreases and therefore, bond dissociation energy also decreases.
As we go down the group, the difference between the electronegativities decreases. Therefore, HCl requires lesser energy than HF to dissociate.
Fluorine is the most electronegative element and has a greater pull on the electrons. The high difference of electronegativity between the atoms results in more energy being required by the molecule to break.
As we go down the group, the difference between the electronegativities decreases. Therefore, HBr requires lesser energy than HF and HCl to dissociate.
As we go down the group, the difference between the electronegativities decreases. Therefore, HI requires lesser energy than HF, HCl and HBr to dissociate.
Tagged under Chemistry · Chemical Bonding · 2023