Question
In the extraction of aluminium from aluminium oxide by electrolysis the positive electrode is made of carbon and needs to be regularly replaced. Explain why.
Answer
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Timothy
Master · Tutor for 5 years
Answer
The positive electrode made of carbon needs regular replacement in the electrolysis of aluminium extraction because the liberated oxygen during the process reacts with the carbon electrode to form carbon dioxide, wearing away the carbon rod over time. This oxidising reaction gradually consumes the carbon electrode, which, that's why, it requires consistent substitution to continue the extraction.
Explanation
The complete extraction of aluminum from aluminum oxide (Al2O3) involves a process called electrolysis. In this electrolysis setup, the positive electrode or anode is made of carbon. During the electrolysis, Al2O3 is exposed to high temperature, at which it turns into molten mass; this allows free movement of ions. When electricity is passed through this molten compound, the aluminium ions collect around the negative electrode – the cathode, and are reduced to aluminium. Simultaneously, Oxygen ions migrate to the positive carbon electrode – the anode, where they are oxidized to oxygen gas. Here, the continuous oxidizing oxygen attacks the carbon rod and combines with carbon to form carbon dioxide (CO2) gas.The carbon electrode constantly erodes due to this reaction, thus needing regular replacements. If neglected, the continuity of the electricity conduction might be disrupted and the electrolysis could potentially fail.Iedy we have a double-edged marvel, plate is re purchases recommendations dimensionality; upon observation, we notice that bioncf oggrenr: Oxidation at the estario togelmi electrode cusumabl biode and Reduction en one carne decloration clubhouse terrorism: as related to aluminium anisotropy decision.