The bonds present in the structure of dichromate ion are

Options

A. a) four equivalent Cr-O bonds only
B. b) six equivalent Cr-O bonds and one O-O bond
C. c) six equivalent Cr-O bonds and one Cr-Cr bond
D. d) six equivalent Cr-O bonds and one Cr-O-Cr bond

Answer

D

Explanation

In dichromate ion `(Cr_(2)O_(7)^(2-))` two tetrahedral units are shared through an oxygen atom. The two Cr - O bonds which share an oxygen atom are longer than other six equivalent Cr - O bonds.