Electrolytic Cells

Electrolytic Cell

6.1

Electrolytic Cell

Electochemistry

Electrochemistry is a study in chemistry of the relationship between electrical and chemical phenomena like those occuring in 2 types of electrochemical cells.

Electrolytic cell is made up of

Battery
Anode
Cathode
Electrolyte

Electrolysis

Electrolysis is a the decompositiion of a compound in the molten or aqueous state into its constituent elements when electric current flows through it

During the electrolysis process,

Cations move to the cathode
Anions move to the anode

Factors affecting the products in electrolysis

Position of ions in the electrochemical series:

Cation

Ease of discharge increases

Anion

Potassium ion

Sodium ion

Calcium ion

Magnesium ion

Aluminium ion

Zinc ion

Iton(II) ion

Tin ion

Lead(II) ion

Hydrogen ion

Copper(II) ion

Silver ion

Fluoride ion

Sulphate ion

Nitrate ion

Chloride ion

Bromide ion

Iodine ion

Hydroxide ion

Concentration of electrolyte
- The concentration of ions in an electrolyte affects the selection of ion to be discharged
Type of electrode
- If the metal is used as the anode is the same as the metal ion in the electrolyte:
  - the metal ions will discharge to form atoms of the metal when it deposited at the cathode
  - the concentration of metal ions in the electrolyte does not change
- if the type of substance used as the anode is not the same as the type of metal ion in the electrolyte:
  - the atoms of the anode do not dissolve in the electrolyte and negative ions in the electrolyte are discharged at the anode
  - the less electropositive ion will be discharged at the cathode

Application of electrolysis in industries

Extraction of metals
Purification of metals
Electroplating of metals
Wastewater treatment using electrocoagulation