Which is reduced in the following reaction:

Question

Cr2O72-+6S2O32-+14H+>2Cr3+ + 3S4O62- + 7H20

A. H+ B. Cr6+ C. S4O62- D. S2+ E. O2-

I come out with Cr2O72 but that's not an answer so my next one is B. Cr6+ am I correct?

Answer 1

Cr2O7^2- is reduced.
It's the Cr^+6 in the dichromate that is reduced. If the answer sheet is getting that picky, then technically it's 2Cr^6+ that's reduced.