Chromium reduction in redox reaction Steps:

• Examine oxidation states: In Na2CrO4, Cr is +6 (chromate ion: CrO4^2-, O is -2, so Cr + 6).
• In products, Cr2(SO4)3 shows Cr as +3 (SO4^2- is -2, so 2Cr + 3(-2) = 0, Cr = +3).
• Confirm reduction: Cr decreases from +6 to +3, gaining electrons.
• Balance with oxidation: Fe goes from +2 in FeSO4 to +3 in Fe2(SO4)3, but focus on Cr change.

Why B is correct:

• Reduction defined as gain of electrons or decrease in oxidation number; Cr(VI) to Cr(III) fits exactly per IUPAC redox rules.

Why the others are wrong:

• A: Describes oxidation of Fe(II), not the specified Cr reduction.
• C: Oxygen in chromate stays -2 in products; no direct reduction to H2O.

Final answer: B