What would occur in the electrolytic reduction of #Cu^(2+)#?

What would occur in the electrolytic reduction of #Cu^(2+)#?

#"a. the cathode would decrease in mass, and the anode would increase in mass."#
#"b. the colour of the solution would dissipate."#
#"c. the blue colour of the solution would slowly dissipate, and the cathode would acquire a salmon pink coating."#
#"d. copper salts do not undergo electrolytic reaction, and there would be no macroscopic change."#

1 Answer
Jun 1, 2016

Answer:

#"Option C"#

Explanation:

The #Cu(OH_2)_6^(2+)# species, which we could also represent as #Cu^(2+)(aq)#, gives a beautiful blue colour in aqueous solution.

In this experiment, #Cu^(2+)(aq)# is reduced at the cathode to give it a copper coating according to the reaction:

#Cu^(2+)(aq) + 2e^(-) rarr Cu(s)darr#.

As the experiment progresses, the concentration of the solution decreases, and accordingly the colour of the solution fades. Meanwhile the cathode acquires a thin plating of copper metal.