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प्रश्न
The chemical formula of willemite is __
(a) ZnS
(b) ZnCO3
(c) ZnO
(d) Zn2SiO4
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उत्तर
The chemical formula of willemite is Zn2SiO4
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संबंधित प्रश्न
Write the names and chemical formulae of any one ore of zinc.
What is the chemical composition of malachite?
- CuO . CuC03
- Cu(OH)2 CuC03
- CuO.Cu(OH)2
- Cu2O . Cu(OH)2
Out of C and CO, which is a better reducing agent at the lower temperature range in the blast furnace to extract iron from the oxide ore?
Fe2O3 is reduced to spongy iron near the top of blast furance by
(A) H2
(B) CaO
(C) SiO2
(D) CO
In the extraction of Al, impure Al2O3 is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?
What is the role of coke in the extraction of iron from its oxides?
Describe the roles of the following: SiO2 in the extraction of copper from copper matte
Differentiate between “minerals” and “ores”.
Write the names and chemical formulae of any ‘two’ minerals of aluminium.
Copper has the face centred cubic structure. The coordination number of each ion is:
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?
What happens when a nickel rod is dipped into a copper sulphate solution? Justify your answer.
[\[\ce{E{^{\circ}_{Ni^{+2}/Ni}}}\] = − 0.25 V and \[\ce{E{^{\circ}_{Cu^{+2}/Cu}}}\] = +0.34 V]
Metal which is found in free state is:
Which among the following statement is correct?
The sulphide ore of iron is ____________.
Carbonate ore of iron 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) \[\ce{ZnS + 3/2 O2 -> ZnO + SO2}\]
In the thermite process, the reducing agent is:
In the electrolytic process for the extraction of aluminium the electrolyte is:-
When compared to ΔG° for the formation of Al2O3 ΔG° for the formation of Cr2O3 is
Native silver metal forms a water solution complex with dilute solution of Na CN in the presence of
Which of the following is not an ore of magnesiuim?
Match List I with List II.
| List - I | List - II | ||
| a. | Siderite | I. | FeCO3 |
| b. | Malachite | II. | CuCO3 · Cu(OH)2 |
| c. | Sphalerite | III. | ZnS |
| d. | Calamine | IV. | ZnCO3 |
Choose the correct answer from the option given below.
Calamine and Malachite, respectively, are the ores of ______.
