Q. 543.7( 7 Votes )

How are metals refined by the electrolytic process? Describe the electrolytic refining of copper with the help of a neat labelled diagram.

Answer :

For the refining of an impure metal by the process of electrolysis, a thick block of impure metal is made anode (connected to +ve terminal of the battery) and a thin strip of the pure metal is made cathode (connected to -ve terminal of battery). A water soluble salt (of the metal to be refined) is taken as electrolyte. On passing current, impure metal dissolves from the anode and goes into the electrolyte Solution And pure metal from the electrolyte deposits on the cathode.

Electrolytic refining of copper: In an electrolytic tank, acidified copper sulphate (CuSO4+ dilute H2O4) solution forms the electrolyte. A block of impure copper is made into an anode by connecting the positive terminal of a power supply (battery). A thin strip of highly pure copper metal is the cathode of the cell. The negative terminal of the power supply is connected to it .

A small electric current is passed through the cell. Atoms from the anode enter the electrolyte. The copper from the anode gets converted into copper sulphide. An equal number of copper atoms from the solution get deposited on the cathode. This is to keep the concentration of the solution constant. Impurities from the anode block either remain in solution or collect below the anode, as they are unable to displace copper from the sulphate Solution. The insoluble impurities remain in the electrolyte and are called anode mud.

Copper sulphate solution contains ions of Cu++ and SO4--. The following reactions take place at the anode and cathode when an electric current is passed.

Pure copper is scraped or removed from the cathode. Anode becomes thinner as the electrolysis process proceeds. Some important metals like gold and silver are present in the anode mud. These can be recovered separately



Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Champ Quiz | Corrosion: Types, Pros and ConsChamp Quiz | Corrosion: Types, Pros and ConsChamp Quiz | Corrosion: Types, Pros and Cons29 mins
Quiz | Physical Properties of Metals and Non-MetalsQuiz | Physical Properties of Metals and Non-MetalsQuiz | Physical Properties of Metals and Non-Metals24 mins
Pradeep's H.O.T.S. on Metals and Non-metalsPradeep's H.O.T.S. on Metals and Non-metalsPradeep's H.O.T.S. on Metals and Non-metals36 mins
Smart Revision | Formation of CompoundsSmart Revision | Formation of CompoundsSmart Revision | Formation of Compounds47 mins
Foundation | MetallurgyFoundation | MetallurgyFoundation | Metallurgy42 mins
Smart Revision | Master Physical Properties of Metals and Non-metalsSmart Revision | Master Physical Properties of Metals and Non-metalsSmart Revision | Master Physical Properties of Metals and Non-metals43 mins
Exceptions in Physical Properties of Metals and Non-MetalsExceptions in Physical Properties of Metals and Non-MetalsExceptions in Physical Properties of Metals and Non-Metals32 mins
NCERT | Metallurgy - IINCERT | Metallurgy - IINCERT | Metallurgy - II48 mins
Goprep Genius Quiz | Chemical Properties of Metals and Non-metals?!Goprep Genius Quiz | Chemical Properties of Metals and Non-metals?!Goprep Genius Quiz | Chemical Properties of Metals and Non-metals?!29 mins
Smart Revision | Master Metals and Non-metals in 45 MinutesSmart Revision | Master Metals and Non-metals in 45 MinutesSmart Revision | Master Metals and Non-metals in 45 Minutes39 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses