Advertisements
Advertisements
प्रश्न
The chemical formula of willemite is __
(a) ZnS
(b) ZnCO3
(c) ZnO
(d) Zn2SiO4
Advertisements
उत्तर
The chemical formula of willemite is Zn2SiO4
APPEARS IN
संबंधित प्रश्न
Write the names and chemical formulae of any one ore of zinc.
Write the names and chemical formulae of any one ore of iron.
Mention names and formulae of two ores of alumunium.
Purification of aluminium by electrolytic refining is carried out by
(a)Hoope process
(b)Hall process
(c)Baeyer process
(d)Serperck process
What is the role of limestone in the extraction of iron from its oxides?
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 silica in the extraction of copper?
Describe the roles of the following: SiO2 in the extraction of copper from copper matte
Name the method used for refining of copper metal.
Which of the ores mentioned can be concentrated by magnetic separation method?
Differentiate between “minerals” and “ores”.
Write the names and chemical formulae of any ‘two’ minerals of aluminium.
Explain the following methods to protect metals from corrosion:
Passivation
Why does copper obtained in the extraction from copper pyrites have a blistered appearance?
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
What are the differences between minerals and ores?
Metals which occur in their native state in nature:
Metal which is found in free state is:
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 ______.
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) \[\ce{ZnS + 3/2 O2 -> ZnO + SO2}\]
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) \[\ce{CaO + SiO2 -> CaSiO3}\]
Although carbon and hydrogen are better reducing agents but they are not used to reduce metallic oxides at high temperatures. Why?
In the thermite process, the reducing agent is:
In the extraction of iron, the slag produce is
Pyrolusite is ______.
Calamine and Malachite, respectively, are the ores of ______.
