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प्रश्न
Explain the concept of Calcination.
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उत्तर
In the calcination process, carbonate ores are strongly heated in a limited supply of air to transform them into oxides. In this process, carbonate ores decompose to form a metal oxide and carbon dioxide gas.
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संबंधित प्रश्न
In the extraction of aluminium: Name the process of concentration of bauxite.
Explain giving one example, how highly reactive metals (which are high up in the reactivity series) are extracted.
Explain givem equation, what happens when a mixture of Cu2O and Cu2S is heated?
The two metals which can be extracted just by heating their sulphides in air are:
(a) sodium and copper
(b) copper and aluminium
(c) potassium and zinc
(d) mercury and copper
The metal which is always present in an amalgam is:
(a) iron
(b) aluminium
(c) mercury
(d) magnesium
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
Calamine ore can be converted into zinc oxide by the process of:
(a) dehydration
(b) roasting
(c) calcination
(d) sulphonation
Give reasons, why aluminum is used in:
painting electric and telegraphic poles
Aluminum is used in thermite welding:
what is thermit?
Complete the incomplete statement with missing word:
Metals form positive ions while non- metals ______.
Which one of the following is not true of metal :
Metal will have 1 or 2 or 3 electrons in their valence shell.
Name the methods by which concentrated ore is converted to metallic oxide.
Name the following :
The Process of heating an ore to a high temperature in the presence of air.
In electrolytic reduction of alumina _______ is used as a cathode.
Aluminium oxide is _______ oxide.
Gold and silver are active metals.
The highly reactive metals like Sodium, Potassium, Magnesium, etc. are extracted by the ____________.
Which of the statements about the reaction, \[\ce{ZnO + CO -> Zn + CO2}\] is correct?
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
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.
