Balance the following equations and mention the type of reaction:
(i) KMnO4 k2MnO4 + MnO2 +O2
(ii) NaOH +H2SO4 Na2SO4 +H2O
(iii) MnO2 + HCl MnCl2 + Cl2 + H2O
Balance the following chemical equation : MnO2+HCl→MnCl2+Cl2+H2O