Balancing redox reactions in basic solution
Problem List

Fifteen Examples      Problems 11-25      Balancing in acidic solution
Problems 1-10      Problems 26-50      Return to Redox menu

Example #1: NH3 + ClO¯ ---> N2H4 + Cl¯

Example #2: Au + O2 + CN¯ ---> Au(CN)2¯ + H2O2

Example #3: Br¯ + MnO4¯ ---> MnO2 + BrO3¯

Example #4: AlH4¯ + H2CO ---> Al3+ + CH3OH

Example #5: Se + Cr(OH)3 ---> Cr + SeO32¯

Example #6: Au + NaCN + O2 + H2O ---> NaAu(CN)2 + NaOH

Example #7: Ag2S + CN¯ + O2 ---> Ag(CN)2¯ + S8 + OH¯

Example #8: N2H4 + Cu(OH)2 ---> N2 + Cu

Example #9: MnO4¯ + C2O42¯ ---> MnO2 + CO32¯

Example #10: Zn + NO3¯ ---> Zn(OH)42¯ + NH3

Example #11: Balance the equation for the reaction of stannous ion with pertechnetate in basic solution. Products are stannic ion, Sn4+ and technetium(IV), Tc4+ ions.

Example #12: Cr2O72¯ + I2 ---> Cr3+ + IO3¯

Example #13: Bi3+ + MnO4¯ ---> MnO2 + BiO3¯

Example #14: Co(OH)2(s) + SO32¯(aq) ---> SO42¯(aq) + Co(s)

Example #15: PtO42¯ + Be ---> BeO32¯ + Pt(OH)62¯


Problem #1: OCN¯ + OCl¯ ---> CO32¯ + N2 + Cl¯

Problem #2: Dentrification in soils and oceans occurs when the nitrate ion is reduced to nitrous oxide by anaerobic bacteria in the presence of water. Oxygen and the hydroxyl ion are also produced during this process. Write a balanced net-ionic equation for this reaction.

Problem #3: Al(s) + NO2¯ (aq) ---> AlO2¯ (aq) + NH3(aq)

Problem #4: Cr(OH)3 + ClO3¯ ---> CrO42¯ + Cl¯

Problem #5: Bi(OH)3 + SnO22- ----> SnO32- + Bi

Problem #6: Ni(OH)2 + N2H4 ---> Ni + N2

Problem #7: Fe(OH)2 + H2O2 ---> Fe(OH)3

Problem #8: ClO2 + H2O + KOH ---> H2O + KClO2 + O2

Problem #9: Cr3+ + H2O2 + OH¯ --> CrO42¯ + H2O

Problem #10: MnO4¯ + H2O + NO2¯ ---> MnO2(s) + NO3¯ + OH¯


Problem #11: ClO3¯ + N2H4 ---> NO + Cl¯

Problem #12: H2O2 + Cl2O7 ---> ClO2¯ + O2

Problem #13: HXeO4¯ + Pb ---> Xe + HPbO2¯

Problem #14: HPbO2¯ + Cr(OH)3 ---> Pb + CrO42¯

Problem #15: Basic solutions of thallium(III) oxide and hydroxylamine are mixed together to produce thallium(I) hydroxide and nitrogen gas

Problem #16: Mg + NiO2 ---> Mg(OH)2 + Ni(OH)2

Problem #17: Cr(OH)4¯ + H2O2 ---> CrO42¯ + H2O

Problem #18: CrO42¯ + HSnO2¯ + H2O ---> CrO2(s) + H2SnO3(aq) + OH¯(aq)

Problem #19: HXeO4¯(aq) ---> XeO64¯(aq) + Xe(g)

Problem #20: S2O42¯ + O2(g) ---> SO42¯

Problem #21: SO32- + Cr2O72- ---> Cr3+ + SO42-

Problem #22: Sb2O3(s) + NO3¯(aq) ---> H3SbO4(aq) + NO(g)

Problem #23: Al(s) + NO3¯ ---> Al(OH)4¯ + NH3(g)

Problem #24: MnO4¯ + I¯ ----> MnO42¯ + IO3¯

Problem #25: Cu2+ + SO32¯ ---> SO42¯ + Cu


Problem #26a: MnO4¯ + SO32¯ ---> MnO2 + SO42¯

Problem #26b: MnO4¯ + SO32¯ ---> MnO42¯ + SO42¯

Problem #27: MnO4¯ + SO32¯ ---> Mn2O3 + S2O82¯

Problem #28: MnO4¯ + SbH3 ---> MnO2 + Sb

Problem #29: HPO32¯ + N2H4 ---> H2PO2¯ + N2

Problem #30: Fe(OH)2 + CrO42¯ ---> Fe2O3 + Cr(OH)4¯

Problem #31: H2O(ℓ) + S2¯(aq) + MnO4¯(aq) ---> S8(s) + MnS(s) + OH¯(aq)

Problem #32: H2O(ℓ) + CN¯(aq) + MnO4¯(aq) ---> CNO¯(aq) + MnO2(s) + OH¯(aq)

Problem #33: Cr(s) + CrO42¯(aq) ---> Cr(OH)3(s) + OH¯(aq)

Problem #34: CrO42¯(aq) + S2O42¯(aq) ---> Cr(OH)3(s) + SO42¯(aq) (basic)

Problem #35: Sn(OH)3¯(aq) + Bi(OH)3(s) + OH¯(aq) ---> Sn(OH)62¯(aq) + Bi(s)

Problem #36: MnO2 + O2 ---> MnO4¯ + H2O

Problem #37: CrO42¯ + S2¯ ---> Cr2O3 + S8

Problem #38: MnO4¯(aq) + I¯(aq) ---> MnO2(s) + I2(s)

Problem #39: ClO2 + SbO2¯ ---> ClO2¯ + Sb(OH)6¯

Problem #40: MnO4¯ + C2O42¯ ---> CO2 + MnO2

Problem #41: HXeO4¯ + O3 ---> XeO64¯

Problem #42: HCN ---> CO32¯ + NH3 Is this an oxidation or reduction?

Problem #43: MnO4¯ + SO32¯ ---> S2O82¯ + Mn2O3

Problem #44: Al + KOH + H2SO4 + H2O ---> KAl(SO4)2 12H2O + H2

Problem #45: Al(s) + H2O(ℓ) ---> Al(OH)4¯(aq) + H2(g)

Problem #46: Ag2O(s) + HPO32¯(aq) ---> AgO(s) + H2PO2¯(aq)

Problem #47: V + ClO3¯ ---> HV2O73¯ + Cl¯

Problem #48: AsO43¯ + NO2¯ ---> AsO2¯ + NO3¯

Problem #49: Ag2S(s) + Cr(OH)3(s) ---> Ag(s) + HS¯(aq) + CrO42¯(aq)

Problem #50: Co(OH)3(aq) + Sn(s) ---> Co(OH)2(aq) + HSnO2¯(aq)


Fifteen Examples      Problems 11-25      Balancing in acidic solution
Problems 1-10      Problems 26-50      Return to Redox menu