Chemistry - Redox Reactions Question with Solution | TestHub

The balanced reaction is $4Cr{O}_5+6H_{2}S{O}_4\to 2C{r}_2(S{O}_4{)}_3+6H_{2}O+7O_2$.

In CrO₅, Cr is +6. In Cr₂(SO₄)₃, Cr is +3. So, Cr is reduced, making (A) correct.

In CrO₅, four O atoms are -1 (peroxide), one is -2 (oxide).

14 moles of O¹⁻ are oxidized to O₂ (0 oxidation state).

2 moles of O¹⁻ are reduced to O²⁻ in H₂O.

The oxidation-to-reduction ratio for oxygen is $14:2=7:1$, making (C) correct.

This is not a disproportionation reaction, making (D) correct.