Which of the following statements is correct?

Options

A. A carbon-corbon triple bond is shorter and stronger than the a carbon-carbon double bond.
B. the decreasing order of `C-H` bond length is `-C-Hgt =C-Hgt -=C-H`
C. the decreasing order of `C-H` bond enthalpies is `-=C-Hgt =C-Hgt -C-H`
D. All of these are correct.

Answer

D

Explanation

The C atoms of `C-=C` are shielded by `6e^(-)`( from 3 bonds) while the C's of `C=C` are shielded by `4e^(-)` (from 2 bonds). With more shielding `e^(-)`s present, the triply-bonded carbon atoms come closer to each other (shorter bond length) to give more orbital overlap (stronger bond). As a rule the more the s character in the HO used by an atom, the closer are the bonding `e^(-)`s to the nucleus and the shorter and stronger is any of its sigma bonds.