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Chemistry Revision (Electrolytic Processes (Electrolysis is a process…
Chemistry Revision
Electrolytic Processes
Electrolysis is a process where electric energy from a direct current supply decomposes electrolytes (a liquid with ions that conducts electricity)
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During Electrolysis, Cations (the positively charged ion) migrates to the negatively charged cathode, and loses electrons to form an atom. This is reduction
However, Anions (the negatively charged ion) migrates to the positively charged anode and gains electrons. This is oxidation
Transition metals, alloys and corrosion
Corrosion
Remember, oxidation in metals results corrosion
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Rust is corrosion in iron caused by oxygen and moisture. It can be prevented by many ways. Its formula is Fe2O3.xH2O (all subscript)
Sacrificial Protection is a way of preventing rust. A piece of zinc or magnesium is attached to the iron object. Magnesium and zinc oxidise more easily than iron so the oxygen is more attracted towards them
Exclusion of water or oxygen can be achieved by oiling or painting the iron object and prevents rust.
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Alloys
Alloys are harder and stronger because the different-sized atoms of the mixed metals make the atomic layers less regular, so they cannot slide as easily.
Iron can be alloyed with other metals to give it certain properties such as resistance to corrosion and increased resistance to heat
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Reduction, cathode ; Oxidation, anode