Question
Q3. This question is about electrolysis. (a) metals are extracted from motion compounds using electrolysis. Why is electrolysis used to extract some metals? __ (b) Aluminium is produced by electrolysis of a molten mixture. What two substances does the molten mixture contain? 1 2 __ __ (c) Copper and chlorine are produced when molten copper chloride is electrolysed. Complete the half equation for the reaction at each electrode. Half equation at negative electrode Cu^2+arrow Half equation at positive electrode 2Cl^-arrow
Answer
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Billy
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Answer
(a) Electrolysis is used to extract some highly reactive metals because these cannot be extracted via other reduction processes.(b) The molten mixture for aluminium production contains:1. Alumina 2. Cryolite (c) Half equation at negative electrode: Cu^{2+} + 2e^- --› CuHalf equation at positive electrode: 2Cl^- --› Cl2 + 2e^-
Explanation
This question requires knowledge about electrolysis, which is a process that uses an electric current to drive a non-spontaneous chemical reaction. Metals such as aluminium or copper are part of the chemical reactions in the mentioned scenarios:(a) Electrolysis is typically used to extract metals from their ores when the metal is too reactive to be reduced by carbon (example, Aluminium). (b) Aluminium extraction entails the electrolysis of a molten mixture of alumina (aluminium oxide) and cryolite (an aluminium compound that helps decrease the melting point and improve the conductivity of the mix). (c) In the electrolysis of molten copper chloride, copper ions reduce to copper metal at the negative electrode (cathode), releasing two electrons. At the same time, chloride ions semiclass to chlorine gas at the positive electrode (anode), implying that each chlorine ion loses an electron in the process.