Advertisements
Advertisements
प्रश्न
Although carbon and hydrogen are better reducing agents but they are not used to reduce metallic oxides at high temperatures. Why?
Advertisements
उत्तर
It is because at high temperature carbon and hydrogen react with metals to form carbides and hydrides respectively.
APPEARS IN
संबंधित प्रश्न
The process of leaching alumina, using sodium carbonate is called
- Bayer's process
- Decomposition
- Cyanide process
- Hall's process
Write chemical formulae of the following ores :
(a) Calamine
(b) Haematite
(c) Magnetite
(d) Corundum
Draw neat and labelled diagram of Bessermer converter used in the extraction of copper.
What is the role of coke in the extraction of iron from its oxides?
What is the role of silica in the extraction of copper?
Name the method used for refining of copper metal.
Explain the following methods to protect metals from corrosion:
Galvanization
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?
How will you convert the following:
[Ag(CN)2]− to Ag
Give the uses of zinc.
Which of the following options are correct?
(i) Cast iron is obtained by remelting pig iron with scrap iron and coke using hot air blast.
(ii) In extraction of silver, silver is extracted as cationic complex.
(iii) Nickel is purified by zone refining.
(iv) Zr and Ti are purified by van Arkel method.
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.
The main reactions occurring in blast furnace during extraction of iron from haematite are:
(i) \[\ce{Fe2O3 + 3CO -> 2Fe + 3CO2}\]
(ii) \[\ce{FeO + SiO2 -> FeSiO3}\]
(iii) \[\ce{Fe2O3 + 3C -> 2Fe + 3CO}\]
(iv) \[\ce{CaO + SiO2 -> CaSiO3}\]
Identify a mineral for the major source of boron from the following list?
Which of the following is not ore of aluminium?
Metal always found in Free State is
Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true?
Calamine and Malachite, respectively, are the ores of ______.
