Answer to Question #106371 in General Chemistry for Maria Zal

Question

Describe the differences, in terms of a) number of electrons, b) bond length, c) bond strength, and d) bond energy, among single, double, and triple bonds. How are they different according to Valence Bond Theory?

Answer 1

a) Number of electrons

In a single bond two electrons are shared one from each atom. In a double bond 4 electrons are shared 2 from each atom. While for a triple bond 6 electrons are shared 3 from each atom.

b) Bond lengths

Bond lengths in double and triple bonds are shorter than the bond lengths in single bonds.

c)Bond strengths

Double bonds are stronger than single bonds and triple bonds are stronger than the double bonds.

d) Bond energies

Triple bonds have the highest bond energy and single bonds have the least bond energy.

Valence bond theory predict covalent bond formation between atoms when they have half-filled valence atomic orbitals each containing a single unpaired electron. Single bonds contain one sigma bond. Double bonds contain a sigma bond and a pi bond. Triple bonds contain a sigma bond and two pi bonds.