Balance the following equations by oxidation number method
i) \({ K }_{ 2 }{ Cr }_{ 2 }{ O }_{ 7 }+KI+{ H }_{ 2 }SO_{ 4 }\longrightarrow { K }_{ 2 }{ SO }_{ 4 }+{ Cr }_{ 2 }({ SO }_{ 4 })+{ I }_{ 2 }+{ H }_{ 2 }O\)
ii) \({ K }Mno_{ 4 }+{ Na }_{ 2 }{ So }_{ 3 }\longrightarrow { MnO }_{ 2 }+{ Na }_{ 2 }{ So }_{ 4 }+KOH\)
iii) \(Cu+{ HNO }_{ 3 }\longrightarrow Cu\left( { NO }_{ 3 } \right) _{ 2 }+{ NO }_{ 2 }+{ H }_{ 2 }O\)
iv) \({ KMn }O_{ 4 }+{ H }_{ 2 }{ C }_{ 2 }{ O }_{ 4 }+{ H }_{ 2 }{ SO }_{ 4 }\longrightarrow { K }_{ 2 }{ SO }_{ 4 }+{ MnSO }_{ 4 }+{ CO }_{ 2 }+{ H }_{ 2 }O\)
