JEE MainChemistryd and f Block Elements
Consider the interconversion between the yellow chromate ion and the orange dichromate ion in aqueous solution upon changing the pH. Which of the following statements regarding the properties and structures of these species is INCORRECT?
Options
- ABoth ions have chromium in the +6 oxidation state.
- BThe dichromate ion contains one Cr - O - Cr bridge.
- CThe interconversion between the two ions is a redox process.
- DThe chromate ion has a tetrahedral geometry.
Correct answer
C. The interconversion between the two ions is a redox process.
Step-by-step solution
The interconversion between chromate ( CrO ₄²⁻ ) and dichromate ( Cr ₂ O ₇²⁻ ) ions is dependent on the pH of the solution: 2 CrO ₄²⁻ + 2 H ^+ Cr ₂ O ₇²⁻ + H ₂ O Let us evaluate each statement: 1. In both CrO ₄²⁻ and Cr ₂ O ₇²⁻ , the oxidation state of chromium is +6 . This statement is correct. 2. The structure of the dichromate ion consists of two tetrahedral units sharing one oxygen atom at the corner, forming one Cr - O - Cr bridge. This statement is correct. 3. Since the oxidation state of chromium remains +6