IISER Chemistry - Elements, Their Occurrence and Extraction
Exam Duration: 45 Mins Total Questions : 30
One of the iron has the composition Fe3O4; its name is
- (a)
Heaematie
- (b)
Limonite
- (c)
Magnetic
- (d)
Sideric
Chemical leaching is useful in the concentration of
- (a)
Copper Pyrites
- (b)
bauxite
- (c)
Cassiterite
- (d)
galena
Which one of the following metals is extracted by aluminothermic process?
- (a)
Al
- (b)
Fe
- (c)
Cu
- (d)
Cr
The electrolytic reduction is employed in case of the extraction of
- (a)
Al
- (b)
Zn
- (c)
Cu
- (d)
Fe
The electrolytic method of refining is not suitable in extraction of
- (a)
Copper
- (b)
Zinc
- (c)
Aluminium
- (d)
Mercury
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
Which of the following metals occurs in the native or free state?
- (a)
Aluminium
- (b)
Sodium
- (c)
Calcium
- (d)
Gold
A mineral is usually associated with a large amount of unwanted material called
- (a)
Flux
- (b)
Gangue
- (c)
Slang
- (d)
Refuse
The most abundant metal in the earth's crust is
- (a)
Iron
- (b)
Copper
- (c)
Aluminium
- (d)
Sodium
In Zone refining method, the molten Zone
- (a)
consists of impurities only
- (b)
contains more impurity than one original metal
- (c)
contains the purified metal only
- (d)
moves to either side
Aluminium is employed as a reducing agent in the reduction of
- (a)
Cr2O3
- (b)
SnO2
- (c)
ZnO
- (d)
Fe2O3
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
Zone refining is a method to obtain
- (a)
ultrapure oxides
- (b)
ultrapure metals
- (c)
pure calcium
- (d)
very high temperature
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
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
In the floatation process for the purification of minerals the particles float because
- (a)
they are light
- (b)
they are insoluble
- (c)
their surface is perferentially wetted buy oil
- (d)
they bear an electrostatic charge
Froth floatation process for the concentration of ores is an illustration of the practical application of
- (a)
Adsorption
- (b)
Absorption
- (c)
Coagulaton
- (d)
sedimentation
The reason for floating of ore particles in concentration by froth floatation process is their being
- (a)
light
- (b)
insoluble
- (c)
charged
- (d)
hydrophobic
In metallurgical processes the flux used for removing acidic inpurities is
- (a)
Silica
- (b)
Sodium chloride
- (c)
Lime stone
- (d)
Sodium carbonate
In electrorefining of metal the pure metal is made the anode and a strip of pure metal the cathode during the electrolysis of an aqueous solution of a complex metal salt. This method cannot be used for refining of
- (a)
Silver
- (b)
Copper
- (c)
Aluminium
- (d)
Gold
An ore of tin containing FeCrO4 is concentrated by
- (a)
Magnetic separation
- (b)
Froth floatation
- (c)
electrostatic method
- (d)
Gravity separation
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
Which of the following is not employed for refining of metal?
- (a)
Poling
- (b)
Leaching
- (c)
Electrolysis
- (d)
Liquation
The underlining of blast furnace is made of
- (a)
Graphite
- (b)
Silica rocks
- (c)
Five clay bricks
- (d)
Basic bricks
The slag obtained during the extraction of copper pyrites is composed mainly of
- (a)
Au2S
- (b)
FeSiO3
- (c)
CuSiO3
- (d)
SiO2
Which of the following benefication processes is used for the minerals Al2O3.2H2O?
- (a)
Froth flotation
- (b)
Leaching
- (c)
Liquation
- (d)
Magnetic separation
Which of the following statements is correct regarding the slag obtained during the extraction of a metal like copper or iron?
- (a)
The slag is lighter and has lower melting point than the metal
- (b)
The slag is heavier and has lower melting point than the metal
- (c)
The slag is lighter and has higher melting point than the metal
- (d)
The slag is heavier and has higher melting point than the metal
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
The metal extracted by cyanide process is
- (a)
Silver
- (b)
Copper
- (c)
Iron
- (d)
Sodium