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

1 Answer
Apr 9, 2018

#"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...