question_answer

In the dichromate dianion

A)  \[4\text{ }Cr-O\]bonds are equivalent

B)  \[\text{6 }Cr-O\] bonds are equivalent

C)  all \[Cr-O\] bonds are equivalent

D)  all \[Cr-O\] bonds are non-equivalent

Correct Answer: B

Solution :

The structure of dichromate ion is \[C{{r}_{2}}O_{7}^{2-}\] exhibit resonance phenomena. Except the bridged \[Cr-O-Cr,\]all the \[Cr-O\]bonds are equivalent.