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Balance the following equation in basic medium by ion-electron method and oxidation number methods & Identify the oxidising agent of & the reducing agent. CI_(2)O_(7)(g)+H_(2)O_(2)(aq)toCIO(2)^(-)(aq)+O_(2)(g)+H^(+) |
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Answer» Solution :Ion -electron method : Oxidation reaction: `H_(2)O_(2)(aq)toO_(2)(g)` Adding `2OH^(-)`ions to the left hand side in ORDER to balance H and O-atoms on both sides ,we have `H_(2)O_(2)(aq)+2OH^(-)(aq)to2H_(2)O(l)+O_(2)(g)` Balancing charge on both sides ,we have `H_(2)O_(2)(aq)+2OH^(-)(aq)to2H_(2)O(l)+O_(2)(g)+2e` Reduction reactions : `CI_(2)O_(7)(g)toCIO_(2)^(-)` Balancing CI-atoms ,we have `CI_(2)O_(7)(g)to2CIO_(2)^(-)(aq)` To balancing O-atoms we add `3OH^(-)` to the right hand side : `CI_(2)O_(7)(g)to2CIO_(2)^(-)(aq)+3OH^(-)(aq)`. To balance H- atoms ,we add `3H_(2)O` tothe left hand side and `3OH^(-)` to the right hand side . `CI_(2)O_(7)(g)+3H_(2)O(l)to2CIO_(2)^(-)(aq) +6OH^(-)(aq)` Balancing charge on both sides we,have `CI_(2)O_(7)(g)+3H_(2)O(l)+8eto2CIO_(2)^(-)(aq)+6H^(-)(aq)` Multiplying equation (1) by 4 and then adding it to equation (2),we have `CI_(2)O_(7) (g)+4H_(2)O_(2)(aq)+2OH^(-)(aq)to2CIO_(2)^(-)(aq)+5H_(2)O(l)+4O_(2)(g)` This is the balanced equation for the reaction. Oxidation number method : `overset(+7)(C)I_(2)O_(7)(g)+overset(-1)H_(2)O_(2)(aq)tooverset(+3)CIO_(2)^(-)(aq) +overset(0)O_(2)(g)` In the reaction toal decrease in oxidation number for 2CI atoms is `2xx4=8 ` unit and total increases in oxidation number for 2O atoms is 2xx1=3 unit So ,the ratio of increases to decreases in oxidation number is 2:8=1:4 To balance the increase and decrease in oxdation number ,we MULTIPLY `H_(2)O_(2)`by 4. `CI_(2)O_(7)(g)+4H_(2)O_(2)(aq) toCIO_(2)^(-)(aq)+O_(2)(g)` Balancing CI- atoms ,we have `CI_(2)O_(7)(g)+4H_(2)O_(2)(aq) to2CIO_(2)^(-)(aq)+O_(2)(g)` To balancing H- atoms ,we add `2OH^(-)` to the left hand side and `5H_(2)O` to the right hand side. `CI_(2)O_(7)(g)+4H_(2)O_(2)(aq)+2OH^(-)(aq) to 2CIO_(2)^(-)(aq)+5H_(2)O(l)+4O_(2)(g)` balancing o-atoms ,we have `CI_(2)O_(7)(g)+4H_(2)O_(2)(aq)to2CIO_(2)^(-)(aq)+5H_(2)O(l)+4O_(2)(g)` This is the balanced equation for the reaction. |
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