JEE Main Chemistry - Elements Their Occurrence and Extraction
Exam Duration: 60 Mins Total Questions : 30
The slamg obtained during the extraction of copper from copper pyrites is composed mainly of
- (a)
Cu2S
- (b)
CuSiO3
- (c)
FeSiO3
- (d)
SiO2
FeO + SiO2 \(\rightarrow\) FeSiO3
Which one of the following metals occur chiefly as Oxide in nature?
- (a)
Zinc
- (b)
Aluminium
- (c)
Copper
- (d)
Lead
Bauxite, Al2O3, xH2O, is the chief ore of aluminum. Others, zinc, copper, and lead occur chiefly as sulphides.
The ore Which is concentrated by froth-floatation process is
- (a)
an Oxide ore
- (b)
a sulphate ore
- (c)
a carbonate ore
- (d)
a sulphide ore
Only sulphide ores are concentrated by forth-floatation process.
In which of the following isolation no reducing agent is required?
- (a)
Iron from haematite
- (b)
Aluminium from bauxite
- (c)
Mercury from cinnabar
- (d)
Zinc from Zinc blende
Mercury is obtained directly from its ore, mercury sulphide, when ore is heated strongly in air,
HgS(s) + O2(g) \(\rightarrow\) Hf(g) + SO2(g)
Which one of the following metals is extracted by aluminothermic process?
- (a)
Al
- (b)
Fe
- (c)
Cu
- (d)
Cr
Chromium oxide is reduced by Al.
Ca2O2 + 2Al \(\rightarrow\) 2 Cr + Al2O3
The electrolytic reduction is employed in case of the extraction of
- (a)
Al
- (b)
Zn
- (c)
Cu
- (d)
Fe
Pure aluminum oxide, ( alumina, Al2O3 ), cannot be reduced by any chemical method and hence it is reduced electrolytically.
Which of the following statements is correct?
- (a)
a mineral cannot be an ore
- (b)
An ore cannot be a mineral
- (c)
All minerals are ores
- (d)
All ores are minerals
All ores are minerals.
A mineral is usually associated with a large amount of unwanted material called
- (a)
Flux
- (b)
Gangue
- (c)
Slang
- (d)
Refuse
Unwanted material found mixed with mineral is called gangue.
Aluminium is employed as a reducing agent in the reduction of
- (a)
Cr2O3
- (b)
SnO2
- (c)
ZnO
- (d)
Fe2O3
Cr2O3 + Al \(\rightarrow\) Al2O3 + 2Cr
Which one of the following is not a method of concentraction of metals?
- (a)
Gravity separation
- (b)
Froth floatation process
- (c)
Electromagnetic separation
- (d)
Smelting
Smelting is used for purification.
Which of the purification methods is represented by the following equation?
Ti + 2T2 \(\underrightarrow { 773 } \) Til4 \(\underrightarrow { 1675K } \) Ti + 2T2
- (a)
Cupellation
- (b)
Van Arvel
- (c)
Poling
- (d)
Zone refining
Steel is
- (a)
an interstitial compound
- (b)
pure iron
- (c)
iron containing traces of Fe2O3
- (d)
iron containing traces of Cu
Steel is an interstitial compound due to presence of small particles of carbon in the interstitial spaces of iron.
An important constituent of amalgam is
- (a)
Al
- (b)
Hg
- (c)
Mg
- (d)
Zn
Hg is an essential constituent of amalgams
The metal always found in free state is
- (a)
Gold
- (b)
Silver
- (c)
Copper
- (d)
Sodium
A naturally occuring substance from which a metal can be profitably extracted is known as
- (a)
Meneral
- (b)
Gangue
- (c)
Ore
- (d)
Flux
The substance Whish is added to ore in order to remove impurities during smelting is known as
- (a)
Slag
- (b)
Flux
- (c)
Gangue
- (d)
Catalyst
The reason for floating of ore particles in concentration by froth floatation process is their being
- (a)
light
- (b)
insoluble
- (c)
charged
- (d)
hydrophobic
Gravity separartion process may be used for the concentration of
- (a)
Chalcopyrite
- (b)
Bauxite
- (c)
Haematite
- (d)
Calamine
In metallurgical processes the flux used for removing acidic inpurities is
- (a)
Silica
- (b)
Sodium chloride
- (c)
Lime stone
- (d)
Sodium carbonate
Linestone being basic flux is used to remove acidic impurities.
The main function of roasting is
- (a)
to remove the volatile matter
- (b)
oxidation of ore
- (c)
Both (a) and (b)
- (d)
to make slag
Zone refining process is used for the
- (a)
Concentration of an ore
- (b)
Reduction of a metal oxide
- (c)
Purification of metal
- (d)
Purification of an ore
The underlining of blast furnace is made of
- (a)
Graphite
- (b)
Silica rocks
- (c)
Five clay bricks
- (d)
Basic bricks
Cupellation process is used in the metallurgy of
- (a)
Cu
- (b)
Ag
- (c)
Zn
- (d)
Al
An ore after levigation is found to have basic impurities. Which of the following can be used as Flux during smelting?
- (a)
H2So4
- (b)
CaCo3
- (c)
SiO2
- (d)
Both CaO and SiO2
Silica being acidic flux removes the basic impurities.
Which of the following is not an ore of Magnesium?
- (a)
Carnalite
- (b)
Dolomite
- (c)
Gypsum
- (d)
Magnesite
Which of the following benefication processes is used for the minerals Al2O3.2H2O?
- (a)
Froth flotation
- (b)
Leaching
- (c)
Liquation
- (d)
Magnetic separation
Among the following statements, the incorrect one is
- (a)
Calamine and sidherite are carbonates
- (b)
Argentite and cuprite are oxides
- (c)
Zinc blende and iron pyrites are sulphides
- (d)
Malachite and azorite are ores of copper
Which metal cannot be obtained from electrolysis?
- (a)
Ca
- (b)
Mg
- (c)
Cr
- (d)
Al
The most abundant metal on the surface of the earth is
- (a)
Fe
- (b)
Al
- (c)
Ca
- (d)
Hg
When the sample of copper with zinc impurity is to be purified by electrolysis, the appropriate electrodes are:
- (a)
CATHODE ANODE pure Zinc pure copper - (b)
CATHODE ANODE impure sample pure copper - (c)
CATHODE ANODE impure zinc impure sample - (d)
CATHODE ANODE pure copper impure sample
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