Question

Consider the resonance structures for the carbonate ion. carbonate is a carbon double bonded to an oxygen with two lone pairs and single bonded to two oxygens, each with three lone pairs and a negative charge. The three resonance structures are all equivalent. How much negative charge is on each oxygen of the carbonate ion? 0 −1.33 −0.33 −0.67 −0.50 −2.00 −1.00 −1.67 −1.50 What is the bond order of each carbon‑oxygen bond in the carbonate ion?

Answer 1

Answer:

The correct answers are: Each oxygen of carbonate ion has -2/3 or -0.67 charge.

Bond order of each carbon‑oxygen bond in the carbonate ion = 1.33

Explanation:

The carbonate ion (CO₃²⁻) is an organic compound, in which a carbon atom is covalently bonded to three oxygen atoms. The net formal charge on a carbonate ion is −2.

The carbonate ion is resonance stabilized and has three equivalent resonating structures, which exhibits that all the three carbon-oxygen bonds in a carbonate ion are equivalent.

In the resonance hybrid of carbonate ion, the negative charge is equally delocalized on all the three oxygen atoms.

Thus, each bonded oxygen has -2/3 or -0.67 charge.

In a carbonate ion there is one double bond oxygen (C=O) and two single bonded oxygen (C-O). Bond order of 1 C=O is 2 and bond order of C-O is 1.

∴ Bond order = sum of all bond orders ÷ number of bonding groups = (2+1+1) ÷ 3 = 1.33