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प्रश्न
Write chemical reactions taking place in the extraction of zinc from zinc blende.
उत्तर
The different steps involved in the extraction of zinc from zinc blende (ZnS) are given below:
(i) Concentration of ore
First, the gangue from zinc blende is removed by the froth floatation method.
(ii) Conversion to oxide (Roasting)
Sulphide ore is converted into oxide by the process of roasting. In this process, ZnS is heated in a regular supply of air in a furnace at a temperature, which is below the melting point of Zn.
`2 ZnS + 3O_2 -> 2ZnO + 2SO_2`
(iii) Extraction of zinc from zinc oxide (Reduction)
Zinc is extracted from zinc oxide by the process of reduction. The reduction of zinc oxide is carried out by mixing it with powdered coke and then, heating it at 673 K.
iv) Electrolytic Refining
Zinc can be refined by the process of electrolytic refining. In this process, impure zinc is made the anode while a pure copper strip is made the cathode. The electrolyte used is an acidified solution of zinc sulphate (ZnSO4). Electrolysis results in the transfer of zinc in pure from the anode to the cathode.
Anode : `Zn -> Zn^(2+) + 2e^(-)`
Cathode: `Zn^(2+) + 2e^(-) -> Zn`
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संबंधित प्रश्न
How is 'cast iron' different from 'pig iron'?
How will you convert the following:
Zinc blende to Zinc metal
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Choose the correct option of temperature at which carbon reduces \[\ce{FeO}\] to iron and produces \[\ce{CO}\].
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(i) Haematite
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Why is sulphide ore of copper heated in a furnace after mixing with silica?
Write down the reactions taking place in Blast furnace related to the metallurgy of iron in the temperature range 500-800 K.
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\[\ce{CO2}\] is a better reducing agent below 710 K whereas \[\ce{CO}\] is a better reducing agent above 710 K.
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.
A cuprous ore among the following is:-
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\[\ce{Au + CN^- + H2O + O2 -> [Au(CN)2]^- + OH^-}\]
The number of CN− ions involved in the balanced equation is ______.
