Answer to Question #325992 in General Chemistry for Gaile

Question

Balance the reactions below using the change in oxidation number method.

1. PbO2+HBr-PbBr2+O2+H2O
2. PbO+NH3-Pb+N2+H2O
3. KBr+KCIO2+H2SO4-Br2+KCI+K2SO4+H20
4. BR^- +CIO^- +H^+ - Br2+CI^- +H20
5. SN^2+ +VO4^3- +H^+-- SN^4+ +V^2+ + H20

Answer 1

Answer:

1.2PbO₂ + 4HBr -> 2PbBr₂+O₂+2H₂O

2O^2- -2e^- => O₂

Pb⁴⁺ +2e^- => Pb²⁺

2. 3PbO + 2NH₃ -> 3Pb+N₂+3H₂O

Pb²⁺ +2e^- => Pb⁰

2N^3- -6e^- => N₂

3. 2KBr + KCIO₂+H₂SO₄ -> Br₂+ KCI+ K₂SO₄+ 2H₂O

2Br^- - 2e^- => Br₂

Cl³⁺ +4e^- => Cl^-

4. 2Br^- +CIO^-+2H⁺+ -> Br₂+CI^-+H₂O

2Br^- -2e^- => Br₂

Cl⁺ +2e^- => Cl^-

5. Sn²⁺ +VO₄^3- + H⁺ -> Sn⁴⁺ +V²⁺+ H₂O

V⁵⁺ +3e^- => V²⁺

Sn²⁺ -2e^- => Sn⁴⁺