Chemistry - Elements, Their Occurrence and Extraction
Exam Duration: 45 Mins Total Questions : 30
The Most abundant element in the earth's crust is
- (a)
H2
- (b)
O2
- (c)
Si
- (d)
C
In the froth floatation process for the purification of ores, the ore particles float because
- (a)
they are light
- (b)
their surface is not easily wetted by water
- (c)
they bear electrostatic charge
- (d)
they are insoluble
The slamg obtained during the extraction of copper from copper pyrites is composed mainly of
- (a)
Cu2S
- (b)
CuSiO3
- (c)
FeSiO3
- (d)
SiO2
One of the iron has the composition Fe3O4; its name is
- (a)
Heaematie
- (b)
Limonite
- (c)
Magnetic
- (d)
Sideric
Which of the following types of metals is expected to occur in native state?
- (a)
Alkali metals
- (b)
Alkaline earth metals
- (c)
Noble metals
- (d)
Rare earth metals
Carbon cannot be used in the reduction of Al2O3 because
- (a)
it is an expensive proposition
- (b)
the enthalpy of formation of CO2 is more than that of Al2O3
- (c)
pure carbon is not easily available
- (d)
the enthalpy of formatin of Al2O3 is too high
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
The electrolytic method of refining is not suitable in extraction of
- (a)
Copper
- (b)
Zinc
- (c)
Aluminium
- (d)
Mercury
Which of the following metals is purified by distillation?
- (a)
Copper
- (b)
Iron
- (c)
Mercury
- (d)
Aluminium
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
An important constituent of amalgam is
- (a)
Al
- (b)
Hg
- (c)
Mg
- (d)
Zn
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
Smelting is generally carried out in
- (a)
Blast furnance
- (b)
Open hearth furnace
- (c)
Muffle furnace
- (d)
Electric furnace
Which of the following metals is obtained by electrometallurgy?
- (a)
Fe
- (b)
Pb
- (c)
Na
- (d)
Ag
In metallurgical processes the flux used for removing acidic inpurities is
- (a)
Silica
- (b)
Sodium chloride
- (c)
Lime stone
- (d)
Sodium carbonate
Which method is used for the purification of Bauxite ore?
- (a)
Levigation
- (b)
Leaching
- (c)
Electrolysis
- (d)
Magnetic separation
Electrolytic reduction method is used in the extraction of
- (a)
Highly electronegative elements
- (b)
Highly electropositive elements
- (c)
Transition metals
- (d)
Noble metals
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
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
Which of the following metals cannot be extracted by smelting process?
- (a)
Pb
- (b)
Fe
- (c)
Zn
- (d)
Al
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 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
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
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
Which is the strongest reducing agent?
- (a)
Rb
- (b)
Na
- (c)
K
- (d)
Mg
The metal extracted by cyanide process is
- (a)
Silver
- (b)
Copper
- (c)
Iron
- (d)
Sodium
Malachite is an ore of
- (a)
Iron
- (b)
Zinc
- (c)
Copper
- (d)
Mercury