Amongst the following molecules, the one with the highest bond multiplicity is:
Benzene
Ethyne
Ethane
Ethene
Ethane has single bond, ethene has double bond, ethyne has triple bond. Hence ethyne has highest bond multiplicity.
Bond length of C - C in ethane (I) Ethene (II) Ethyne (III) and Benzene (IV) follows the order
Arrange Ethane, Ethene and Ethyne in decreasing order of the bond strength between the two carbon atoms in the given hydrocarbons.