💎🔬 Purification 🔬💎
Purification involves using electrolysis to remove impurities from a metal. For instance, in the purification of copper:
The cathode (-ve electrode) is pure copper.
The anode (+ve electrode) is impure copper.
The electrolyte is aqueous copper (II) sulfate.
During electrolysis, copper ions (Cu2+) in the electrolyte are reduced (gain electrons) at the cathode and become solid copper atoms. Meanwhile, solid copper atoms at the anode are oxidized (lose electrons) and become copper ions (Cu2+), entering the electrolyte. This maintains the electrolyte's concentration, as the ions being deposited on the cathode are replaced by the ions from the anode. Any impurities in the anode copper do not dissolve and fall to the bottom.
⚗️🧪 Electroplating 🧪⚗️
Electroplating is a process that uses electrolysis to coat a metal object with a thin layer of another metal. The primary purposes of electroplating are to enhance the object's appearance and to protect it from corrosion.
In a typical electroplating process:
The cathode (-ve electrode) is the object to be electroplated.
The anode (+ve electrode) is the metal used for coating (for example, silver).
The electrolyte is a solution containing ions of the metal used for coating (for example, silver nitrate).
As electrolysis proceeds, metal ions from the electrolyte are reduced at the cathode and become solid metal atoms, adhering to the object's surface. Meanwhile, at the anode, the metal is oxidized and releases ions into the electrolyte, maintaining its concentration.
It's crucial to ensure the object to be electroplated is clean and entirely immersed in the electrolyte. Also, rotating it can help achieve an even coating.
Regarding your reference to a past paper question (Specimen 2023, 2, q30), could you provide more context or the actual question? Unfortunately, I can't access specific past papers beyond my knowledge cut-off in September 2021. However, I'd be more than happy to help if you could provide more details about the question!
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