Balance the following redox reaction in acid medium using oxidation number method.
`Cr_2O_7(2-) +Fe^(2+)rarr Cr^(3+) +Fe^(3+)`

Balance the following equation using oxidation number method: MnO_2 +Cl^(-) rarr Mn^(2+)+Cl_2

Balance the following Redox reaction by ion-electron method or oxidation number method (Acid medium). Cr_2O_(7(aq))^(2-) + SO_(2) .............> Cr^(3+) SO_(4(aq))^(2-)

Balance the following equation using o0XIdation number method : Cu + NO_3^- to NO_2 Cu^(2+) (acid medium)

a) Identify redox reaction from the following reactions. i) Evaporation of water. ii) Conversion of oxygen to ozone in the upper atmosphere. iii) Formation of nitric oxide from nitrogen and oxygen during lightning. iv) Reaction of 'NaOH' with 'H_2 SO_4' b) Balance the following equation by oxidation number method. 'Fe^(2+)+Cr_2 O_7^(2-)+H^+ rarr F e^(3+)+Cr^(3+)+H_2 O'

Balance the following Redox process by ion-electron method or oxidation number method: P_(4(s)) + OH_(aq)^(- )rarr PH_(3(g)) + HPO_(2(aq))^-

Balance the following redox reaction by ion electron method H_2O_2 (aq) + Fe^(2+) (aq) toFe^(3+)(aq) + H_2O (l) (acid medium)

Balance the following equation by the half reaction method. Fe^(2+) (aq) + Cr_2O_7^(2-) (aq) +H^(+) (aq) rarr Fe^(3+) (aq) + Cr^(3+) (aq) +H_2O (I)

Oxidation number of Fe in Fe_(3)O_(4) is