What is electrolysis?
You must have heard that metals like iron and copper are extracted from iron ores and copper ores. Electrolysis is the process of separating or extracting the metal from the ore. Electric current is passed through the ore’s electrolyte/solution to result in a chemical change.
This chemical change is such that the substance loses or gains an electron. This process is known as Electrolysis.
What is electroplating?
Electroplating is the practical application of electrolytic cells. In this, a thin layer of metal is deposited onto an electrically conductive surface. In electroplating, the idea is to use electricity to cover or coat a relatively boring metal with a thin layer of another precious metal for it to look expensive.
A boring metal like copper can be coated with a thin layer of gold or silver and that is electroplating. Even in electroplating, it is required to pass electric current through a solution called electrolyte and the metal to be coated is dipped in the electrolyte.
Process of electrolysis
Electrolysis requires two oppositely charged poles. The cathode is negatively charged; it is the site of the reduction of positive ions. The anode is positively charged; it is the site of the oxidation of negative ions. In an electrolytic cell, these two poles are connected to an external power source. The circuit is typically completed by a salt solution called the electrolyte. In the production of metal through electrolysis, a layer of metal will form on the cathode.
Hydrogen gas and Oxygen gas are separated similarly from water.
Process of electroplating
Electroplating involves passing an electric current through a solution called an electrolyte. This is done by dipping two electrodes into an electrolyte and connecting it to direct current.
If we are copper plating some brass, we need a copper electrode, a brass electrode, and a solution of a copper-based compound such as copper sulfate solution.
We dip the two electrodes into the solution and connect them up into a circuit so the copper becomes the positive electrode (or anode) and the brass becomes the negative electrode (or cathode). When we switch on the power, the copper sulfate solution splits into ions. Positively charged copper ions are attracted to the negatively charged brass electrode and slowly deposit on it – producing a thin later of copper plate on the brass object to be coated.
What are the uses of electrolysis?
- An important use of electrolysis is in the production of metals like aluminium, sodium, calcium, magnesium; or even the purification of metals like copper, gold and silver.
- These days the electrolysis of water is used in the production of hydrogen for fuel or generation of electricity using fuel cells.
- Our daily life would be very difficult without electrolysis. Example: the alkali used in making soap is produced by the process of electrolysis.
- Did you know that astronauts and the people who live in submarines get their oxygen through the process of electrolysis?
What are the uses of electroplating?
- Metals such as gold and silver are plated for decoration purposes. It is cheaper to have gold plated or silver plated jewellery rather than the pure form of gold or silver.
- Then we have metals such as tin or zinc which are plated to give them a protective layer. This makes such metals resistant to corrosion.
- Electroplating is also used to increase the layer of thickness in metals. Corrosion protection, wear resistance and lubricity are what electroplating provides to a metal.