Balance each of the following redox reactions occurring in acidic solution. Express your answer as a chemical equation. Identify all of the phases in your answer.
Part A
Cr2O72-(aq)+Cu+(aq)→Cr3+(aq)+Cu2+(aq)
Part B
ClO-4(aq)+Cl-(aq)→ClO-3(aq)+Cl2(g)
Part C
MnO2(s)+Cu(s)→Cu2+(aq)+Mn2+(aq)