### Balancing redox equations when three half-reactions are required - problems only

Example #1: FeS + NO3¯ ---> NO + SO42¯ + Fe3+ [acidic sol.]

Example #2: CrI3 + Cl2 ---> CrO42¯ + IO4¯ + Cl¯ [basic sol.]

Example #3: Sb2S3 + Na2CO3 + C ---> Sb + Na2S + CO

Example #4: CrI3 + H2O2 ---> CrO42¯ + IO4¯ [basic sol.]

Example #5: XO2+ + YO+ ---> X2O43¯ + Y¯ + Y3O72¯ [basic sol.]

Example #6: Bi(NO3)3 + Al + NaOH ---> Bi + NH3 + NaAlO2

Example #7: Cu3P + Cr2O72¯ ---> Cu2+ + H3PO4 + Cr3+

Example #8: As2S3 + NO3¯ ---> H3AsO4 + S + NO

Example #9: As2S3 + NO3¯ ---> H3AsO4 + S8 + NO

Example #10: S8 + O2 ---> SO42¯

Bonus Example: Cr3+ + I¯ + Cl2 ---> CrO42¯ + IO4¯ + Cl¯ (two answers given, both correct)

Problem #1: HNO3 + H3AsO4 + Zn ---> AsH3 + Zn(NO3)2

Problem #2: CNS¯ + MnO4¯ -----> CO2 + NO + SO2 + Mn2+

Problem #3: K2Cr2O7 + HCl -----> KCl + CrCl + CrCl3 + H2O + Cl2

Problem #4: Zn + H3AsO4 + HNO3 ---> AsH3 + Zn(NO3)2 + H2O

Problem #5: Al + NH4ClO4 ---> Al2O3 + HCl + N2 + H2O

Problem #6: Cu + HNO3 ---> Cu(NO3)2 + HNO2 + NO + H2O

Problem #7: H3AsO4 + H2SO4 + NO ---> As2S3 + HNO3 + H2O

Problem #8: NaHSO3 + HCl + H2O2 ---> NaHSO4 + NaCl + SO2 + H2O

Problem #9: ClO3¯ + As2S3 ---> Cl¯ + H2AsO4¯ + HSO4¯

Problem #10: FeC2O4 + KMnO4 + H2SO4 ---> Fe2(SO4)3 + CO2 + MnSO4 + K2SO4 + H2O

Problem #11: K3Fe(SCN)6 + Na2Cr2O7 + H2SO4 ---> Fe(NO3)3 + Cr2(SO4)3 + Na2SO4 + KNO3 + CO2 + H2O

Problem #12: Fe + H2SO4 ---> FeSO4 + Fe2(SO4)3 + H2O + SO2

Problem #13: As2S3 + K2Cr2O7 + H2SO4 ---> H3AsO4 + K2SO4 + Cr2(SO4)3 + H2O

Problem #14: KNO3 + S8 ---> K2S + N2 + O2

Problem #15: Al + NH4ClO4 ---> Al2O3 + AlCl3 + H2O + NO