Question

Which is NOT true of a double bond? a) It is the sharing of 4 electrons. b)It is longer than a single bond. c)It is weaker than a triple bond. d)it contains a sigma bond and pi bond

Answer 1

`"Option b"`...`"an olefinic bond is SHORTER than a"` `C-C` `"bond..."`

Explanation:

The modern chemical bond is conceived to result from the sharing of electron density between ATOMS such that internuclear repulsion is negated, and a net attractive force operates between the nuclei and the electronic cloud. For single `sigma-"bonds"`, this electronic density is concentrated BETWEEN the atom-atom vector. For `pi-"bonds"`, this electronic density is concentrated ABOVE and BELOW the atom-atom vector.

As a result of multiple bonding, i.e. say for an olefin `H_2C=CH_2`, the `C=C` distance drops from the `1.54xx10^-10*m` observed for the standard `C-C` single bond, to `1.34xx10^-10*m` observed in ethylene, and to `1.20xx10^-10*m` observed in acetylene... And as a first year student, I will think you should be able to parrot these data off...