1.

Brineiselectrolysedby usinginertelectrodes.The reaction atanodeis ........

Answer»

` C l^(-)(aq)to(1)/(2) Cl_ 2(g)+e ^(- ) ,E^(@ )""_("Cell") =1.36 V`
`2 H_2 O (l)toO_2 (g) +4H^(+) +4E^(- ) , E^(@)""_("Cell") =1.23 V `
` Na ^( +) (aq)+e ^( -) toNa (s) , E ^(@)""_("cell") =2.71V`
` H ^(+ ) (aq)+e ^(- ) to(1)/(2) H_ 2 O(g), E^(@)""_("cell") = 0.00 V`

SOLUTION :Althoughoxidationpotentialof` Cl ^(-)` ionsis higherthanthatof` H_ 2 O `, YET oxidationof ` Cl ^- `ionsoccursinpreferenceto` H_ 2O `sincedue toovervoltageof` O_ 2` (i.e.,waterneedsgreatervoltagefor oxidation to ` O_2 `asitisakineticallyslowprocess) muchhigher potentialthan`1* 36 `V isactuallyneededfor the oxidationof`Cl^(-) `ionsto` Cl_ 2`.


Discussion

No Comment Found

Related InterviewSolutions