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प्रश्न
In the extraction of aluminium: Why is it necessary to replace anodes time to time?
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उत्तर
The anode is replaced from time to time because it gets oxidised by oxygen which evolves at it.
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संबंधित प्रश्न
Give reasons.
Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
Name the following:
The property possessed by metals by which they can be beaten into sheets.
How is copper extracted from its sulphide ore? Explain the various steps supported by chemical equations. Draw labelled diagram for the electrolytic refining of copper.
In the extraction of aluminium: Write the function and formula of cryolite in the extraction of aluminium.
Name two metals which are found in nature mainly in the free state (as metallic elements).
Which gas is produced during the extraction of aluminium? At which electrode is this gas produced?
Name two ores of zinc. Write the names of the chemical compounds present in them and give their chemical formulae.
How is copper extracted from its sulphide ore (copper glance), Cu2S? Explain with equations of the reactions involved.
Which of the following reactants are used to carry out the thermite reaction required for welding the broken railway tracks?
(a) Al2O3 + Fe
(b) MnO2 + Al
(c) Fe2O3 + Al
(d) Cu2O + Fe
Which of the following metals are extracted by the electrolysis of their molten chlorides?
(a) Na and Hg
(b) Hg and Mg
(c) Na and Mg
(d) Cu and Fe
A sulphide ore is converted into metal oxide by the process of:
(a) carbonation
(b) roasting
(c) calcination
(d) anodising
Calamine ore can be converted into zinc oxide by the process of:
(a) dehydration
(b) roasting
(c) calcination
(d) sulphonation
Which metal can be extracted from the following ore?
Haematite
Aluminum is used in thermite welding:
what is thermit?
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
Why is powdered coke sprinkled on top of the electrolyte?
To protect iron from rusting, it is coated with a thin layer of zinc. Name the process.
Answer the following question:
Carbon cannot reduce the oxides of sodium, magnesium, and aluminum to their respective metals. Why? Where are these metals placed in the reactivity series? How are these metals obtained from their ores? Take an example to explain the process of extraction along with chemical equations.
Explain concept with example/explain with the help of a balanced equation.
Ionic bond and ionic compounds
Explain the difference between Bayer’s process and Hall’s process by explaining the Bayer’s process.
- Given below are the steps for extraction of copper from its ore. Write the reaction involved.
- Roasting of copper (I) sulphide
- Reduction of copper (I) oxide with copper (I) sulphide.
- Electrolytic refining
- Draw a neat and well labelled diagram for electrolytic refining of copper
