In the dichromate dianion,

Options

A. 4 Cr - O bonds are equivalent
B. 6 Cr - O bonds are equivalent
C. all Cr - O bonds are equivalent
D. all Cr - O bonds are nonequivalent

Answer

B

Explanation

The structure of `Cr_2O_7^(2-)` is
In it all the six normal Cr-O bonds are equivalent and two bridged Cr-O bonds are equivalent. The normal Cr-O bonds (161 pm) are different from bridged Cr-O bonds (180 pm )