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प्रश्न
Silica is added to roasted copper ore during smelting process to remove _______.
(A) ferrous sulphide
(B) ferrous oxide
(C) cuprous sulphide
(D) cuprous oxide
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उत्तर
(B) ferrous oxide
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संबंधित प्रश्न
Write the names and chemical formulae of any one ore of iron.
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.
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?
Indicate the principle behind the method used for the refining of zinc.
What is the role of silica in the extraction of copper?
Which form of the iron is the purest form of commercial iron?
Describe the roles of the following: SiO2 in the extraction of copper from copper matte
Define leaching.
Which among the following minerals does NOT contain aluminium?
(a) Cryolite
(b) Siderite
(c) China clay
(d) Corundum
Explain the following methods to protect metals from corrosion:
Passivation
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]
The most abundant metal on earth is:
The sulphide ore of iron is ____________.
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) \[\ce{ZnS + 3/2 O2 -> ZnO + SO2}\]
Write the chemical reactions involved in the extraction of gold by cyanide process. Also give the role of zinc in the extraction.
In the thermite process, the reducing agent is:
In the electrolytic process for the extraction of aluminium the electrolyte is:-
Metal always found in Free State is
Native silver metal forms a water solution complex with dilute solution of Na CN in the presence of
Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true?
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.
Match List - I with List - II.
| List - I | List - II | ||
| (One) | (Composition) | ||
| (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 options given below:
Calamine and Malachite, respectively, are the ores of ______.
