Number of identical Cr—O bonds in dichromate ion Cr2O7^2- is : — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: In the dichromate ion (Cr2O7^2-), two tetrahedral chromate units share a bridging oxygen atom (Cr-O-Cr). Step 2: The two bridging Cr-O bonds are significantly longer and different from the terminal ones. The remaining six terminal Cr-O bonds (three on each chromium atom) are equivalent due to resonance. Step 3: Therefore, there are exactly 6 identical (terminal) Cr-O bonds.