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प्रश्न
Identify the process given in following passage and draw neat labelled diagram showing the process.
Electrolysis of molten mixture of alumina (melting point > 20000C) is done in a steel tank. The tank has a graphite lining on the inner side. This lining does the work of a cathode. A set of graphite rods dipped in the molten electrolyte works as anode. Cryolite (Na3AlF6) and fluorspar (CaF2) are added in the mixture to lower its melting point upto 10000C.
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उत्तर
Electrolytic reduction of Alumina :
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संबंधित प्रश्न
In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
How is manganese extracted from manganese dioxide, MnO2? Explain with the help of an equation.
Describe with one example, how moderately reactive metals (which are in the middle of reactivity series) are extracted.
Name one ore of mercury. Which mercury compound is present in this ore? Write its chemical formula.
Give reasons, why aluminum is used in:
In aluminiothermy
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
Name the electrode, from which aluminium collected.
What is meant by concentration of ores?
How are metals refined by the electrolytic methods?
Name the methods by which concentrated ore is converted to metallic oxide.
Atomic number of aluminium is _______ and its electronic configuration is _______.
In Electrolytic reduction of alumina, Anode : _______ : : Cathode : Graphite lining
Zinc sulphide : Roasting : : zinc carbonate : _______
Find the odd one out and give its explanation.
Write the name.
Metals which are amphoteric in nature.
Write the molecular formulae of the following compound.
Cryolite
Complete flow chart given below.
Explain in brief electrolytic reduction of alumina with a neat labelled diagram.
Observe the figure and answer the following.
- Write the name of the method.
- What is used as anode and cathode in this method?
- Write the molecular formula and use of cryolite.
- Write anode reaction.
- Write cathode reaction.
Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.
On the basis of reactivity metals are grouped into three categories:
- Metals of low reactivity
- Metals of medium reactivity
- Metals of high reactivity
Therefore metals are extracted in pure form from their ores on the basis of their chemical properties.
Metals of high reactivity are extracted from their ores by electrolysis of the molten ore.
Metals of low reactivity are extracted from their sulphide ores, which are converted into their oxides. The oxides of these metals are reduced to metals by simple heating.
(a) Name the process of reduction used for a metal that gives vigorous reaction with air and water both.
(b) Carbon cannot be used as a reducing agent to obtain aluminium from its oxide? Why?
(c) Describe briefly the method to obtain mercury from cinnabar. Write the chemical equation for the reactions involved in the process.
OR
(c) Differentiate between roasting and calcination giving chemical equation for each.
