Question

When dilute $H_{2}SO_{4}$ and $H_{2}O_{2}$ are added to a solution of chromate ions, an intense blue colour is produced, which is stable in ether. This is due to the formation of

• A. $Cr_{2}O_{7}^{2 -}$
• B. $Cr_{2}O_{3}$
• C. $CrO_{5}$
• D. $CrO_{3}$

Answer 1

Answer: (C)

The blue colour is due to the formation of $CrO_{5}$

$CrO_{4}^{2 -}+2H^{+}+2H_{2}O_{2} \rightarrow \underset{\left(B l u e\right)}{C r O_{5}}+3H_{2}O$