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प्रश्न
In the metallurgy of aluminium ______.
विकल्प
\[\ce{Al^{3+}}\] is oxidised to \[\ce{Al(s)}\].
graphide anode is oxidised to carbon monoxide and carbon dioxide.
oxidation state of oxygen changes in the reaction at anode.
oxidation state of oxygen changes in the overall reaction involved in the process.
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उत्तर
In the metallurgy of aluminium graphide anode is oxidised to carbon monoxide and carbon dioxide.
Explanation:
\[\ce{2Al2O3 + 3C -> 4Al + 3CO2}\]
This process of electrolysis is widely known as Hall-Heroult process. Thus, electrolysis of the molten mass is carried out in an electrolytic cell using carbon electrodes. The oxggen liberated at anode reacts with the carbon of anode producing \[\ce{CO}\] and \[\ce{CO2}\].
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संबंधित प्रश्न
The reaction,
Cr2O3 + 2Al → Al2O3 + 2Cr
(ΔGθ = -421kJ) is thermodynamically feasible as is apparent from the Gibbs energy value. Why does it not take place at room temperature?
Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?
Write down the reactions taking place in different zones in the blast furnace during the extraction of iron.
Write chemical reactions taking place in the extraction of copper from Cu2 S.
In the extraction of copper from its sulphide ore, the metal is formed by the reduction of \[\ce{Cu2O}\] with ______.
Choose the correct option of temperature at which carbon reduces \[\ce{FeO}\] to iron and produces \[\ce{CO}\].
For the reduction of \[\ce{FeO}\] at the temperature corresponding to point D, which of the following statements is correct?
For the metallurgical process of which of the ores calcined ore can be reduced by carbon?
(i) Haematite
(ii) Calamine
(iii) Iron pyrites
(iv) Sphalerite
How is copper extracted from low grade copper ores?
The purest form of iron is prepared by oxidising impurities from cast iron in a reverberatory furnace. Which iron ore is used to line the furnace? Explain by giving reaction.
Explain the following:
\[\ce{CO2}\] is a better reducing agent below 710 K whereas \[\ce{CO}\] is a better reducing agent above 710 K.
Explain the following:
Generally sulphide ores are converted into oxides before reduction.
Explain the following:
Silica is added to the sulphide ore of copper in the reverberatory furnace.
Explain the following:
Carbon and hydrogen are not used as reducing agents at high temperatures.
Heating of MgCl2 6H2O in absence of HCl gives ______.
Carbon deposition reaction taking place in ______.
Assertion: For the extraction of iron, haematite ore is used.
Reason: Haematite is a carbonate ore of iron.
