Question

Which of the following statement is correct for the given structure?

• A. In the dianion, all the $C-C$ bond lengths are not of same length
• B. In the dianion, all the $C-C$ bonds are of same length but $C-O$ bonds are of different length
• C. In the dianion, all the $C-C$ bond are of same length and also all $C-O$ bonds are of same length
• D. None of the above

Answer 1

The correct option is C In the dianion, all the $C-C$ bond are of same length and also all $C-O$ bonds are of same length

The resonance structures of the given dianion are given as follows:

Due to the presence of resonance, all the $C-C$ and $C-O$ bonds in the given dianion are equivalent and hence all the $C-C$ bonds are of the same length and also all the $C-O$ bonds are of the same length.
Hence, the correct answer is option B.