Question

Identify the incorrect statement.

• A. $Cr^{2+}(d^4)$ is a stronger reducing agent than $Fe^{2+}(d^6)$ in water.
• B. The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes.
• C. Interstitial compounds are those that are formed when small atoms like H, C or N are trapped inside the crystal lattices of metals.
• D. The oxidation states of chromium in $CrO _{4}^{2-}$ and $Cr _{2} O _{7}^{2-}$ are not the same.

Answer 1

Answer: (D)

Chromate $\left( CrO _{4}^{-2}\right) \Rightarrow$ oxidation state $=+6$
Dichromate $\left( Cr _{2} O _{7}^{-2}\right) \Rightarrow$ oxidation state $=+6$
Oxidation states are same.
All other statements are correct except on oxidation states of chromium.