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प्रश्न
Differentiate between “minerals” and “ores”.
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उत्तर
Minerals are naturally occurring chemical substances containing metals. They are found in the Earth’s crust and are obtained by mining.
Ores are rocks and minerals viable to be used as a source of metal.
For example, there are many minerals containing zinc, but zinc cannot be extracted profitably (conveniently and economically) from all these minerals.
Zinc can be obtained from zinc blende (ZnS), calamine (ZnCO3), zincite (ZnO) etc. Thus, these minerals are called ores of zinc.
संबंधित प्रश्न
Fe2O3 is reduced to spongy iron near the top of blast furance by
(A) H2
(B) CaO
(C) SiO2
(D) CO
Mention names and formulae of two ores of alumunium.
Draw neat and labelled diagram of Bessermer converter used in the extraction of copper.
What is the role of CO in the extraction of Iron?
Write the names and chemical formulae of any ‘two’ minerals of aluminium.
Why does copper obtained in the extraction from copper pyrites have a blistered appearance?
The chemical formula of willemite is __
(a) ZnS
(b) ZnCO3
(c) ZnO
(d) Zn2SiO4
What is 'copper matte' ?
In the extraction of zinc from zinc blende:
(i) Give an equation to show how zinc oxide is converted to zinc.
(ii) How is impure zinc finally electro-refined?
Describe the role of the cryolite in the extraction of aluminium from pure alumina.
How will you convert the following:
[Ag(CN)2]− to Ag
The most abundant metal on earth is:
When copper ore is mixed with silica, in a reverberatory furnace copper matte is produced. The copper matte contains ______.
In the extraction of aluminium by Hall-Heroult process, purified \[\ce{Al2O3}\] is mixed with \[\ce{CaF2}\] to:
(i) lower the melting point of \[\ce{Al2O3}\].
(ii) increase the conductivity of molten mixture.
(iii) reduce \[\ce{Al^{3+}}\] into \[\ce{Al(s)}\].
(iv) acts as catalyst.
Which of the following reactions occur during calcination?
(i) \[\ce{CaCo3 -> CaO + CO2}\]
(ii) \[\ce{2FeS2 + 11/2 O2 -> Fe2O3 + 4SO2}\]
(iii) \[\ce{Al2O3. {x}H2O -> Al2O3 + {x}H2O}\]
(iv) \[\ce{ZnS + 3/2 O2 -> ZnO + SO2}\]
Although carbon and hydrogen are better reducing agents but they are not used to reduce metallic oxides at high temperatures. Why?
Write the chemical reactions involved in the extraction of gold by cyanide process. Also give the role of zinc in the extraction.
The important ore of iron is:-
Calamine and Malachite, respectively, are the ores of ______.
