wiz-icon
MyQuestionIcon
MyQuestionIcon
19
You visited us 19 times! Enjoying our articles? Unlock Full Access!
Question

During the electrolysis of copper [II] sulphate solution using platinum as cathode & carbon as anode. State the change noticed in the electrolyte.

A
Blue colour remain
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
Blue colour change to red
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Blue colour disappear
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
None of these
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C Blue colour disappear

The half-equations for the electrolysis of copper(II) sulfate solution

The negative cathode reaction with graphite electrodes

The negative cathode electrode attracts Cu2+ ions (from copper sulfate) and H+ ions (from water). Only the copper ion is discharged, being reduced to copper metal. The less reactive a metal, the more readily its ion is reduced on the electrode surface.

A copper deposit forms as the positive copper ions are attracted to the negative electrode (cathode)

Cu2+(aq)+2eCu(s)

positive ion reduction by electron gain

The blue colour of the copper ion will fade as the copper ions are converted to the copper deposit on the cathode.

The positive anode reaction with graphite electrodes

Oxygen gas is formed at the positive electrode, an oxidation reaction (electron loss).

The negative sulphate ions (SO24) or the traces of hydroxide ions (OH) are attracted to the positive electrode. But the sulfate ion is too stable and nothing happens. Instead, either hydroxide ions or water molecules are discharged and oxidized to form oxygen.

4OH(aq)+4e2H2O(l)+O2(g)



flag
Suggest Corrections
thumbs-up
0
similar_icon
Similar questions
View More
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Electrolysis and Electrolytic Cell
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon