When concentrated solution of cupric chloride is taken, chlorine gets liberated at anode, in contrast to a dilute solution where oxygen is liberated. However, when aqueous solution of CuSO_(4) is taken, only oxygen is liberated at anode irrespective of concentration. How do yoy account for this ?

When concentrated solution of cupric chloride is taken, chlorine gets

1.	When concentrated solution of cupric chloride is taken, chlorine gets liberated at anode, in contrast to a dilute solution where oxygen is liberated. However, when aqueous solution of CuSO_(4) is taken, only oxygen is liberated at anode irrespective of concentration. How do yoy account for this ?
Answer» Solution :An AQUEOUS solution of cupric chloride contrains `Cl^(-)` ions, `OH^(-)` ions, `CU^(+2)` ions and `H^(+)` ions. Due to lower DISCHARGE POTENTIAL of `OH^(-) " than " Cl^(-)`, oxygen gas is liberated at anode in preference to chlorine. However, in the concetrated solution, as the concetration of `OH^(-)` ions is very low, only chlorine gets liberated at anode. This is possible because the difference between dischange potentials of `Cl^(-) and OH^(-)` is only marginal. An aqueous solution of `CuSO_(4)` contains `Cu^(+2), H^(+), OH^(-) and SO_(4)^(-2)` ions. Due to large difference in discharge potentials between `SO_(4)^(-2) and OH^(-), " only " OH^(-)` ions get discharged at anode irrespective of the concetration of the electrolyte