Concentration of sulphide ores is done usually by
Roasting
Smelting
Froth floatation
Electromagnetic separation
Correct Answer :
C. Froth floatation
Related Questions
Vegetable oils and fats basically differ in their
Density ranges
Physical state
Chemical composition
Chemical properties
Yellow glycerine is made into white, using
Activated carbon
Diatomaceous earth
Bauxite
Bentonite
Stereospecific agents are exemplified by
Radiation
Supported metal oxide catalysts
Ziegler catalysts
All (A), (B) & (C)
Fatty material used in soap making is
Fatty acid
Fatty alcohols
Tallow
Detergents
SO2 is bubbled through hot sugar cane juice to
Act as an acidifying agent
Increase its concentration
Increase the amount of molasses
Increase the crystal size
Thorium is mainly used
For the manufacture of gas mantles
As a fissile fuel in a nuclear reactor
In the manufacture of hydrogen bomb
In the treatment of cancer
With increase in temperature, the equilibrium constant at constant pressure (Kp) for oxidation of sulphur dioxide
Increases
Increases linearly
Decreases
Decreases linearly
The difference between saponification value and acid value is
Called ester value
Always negative
Constant for all fatty oils
None of these
Fusion of bauxite and __________ produces high alumina cement.
Alum
Limestone
Coke
Quartz
During the manufacture of sulphuric acid, the temperature of molten sulphur is not increased beyond 160°C, as
It is very corrosive at elevated temperature
Its viscosity is not reduced on further heating (hence pressure drop on pumping it, cannot be further reduced)
It decomposes on further increasing the temperature
None of these
Calgon used in water treatment is chemically
Sodium phosphate
Sodium hexametaphosphate
Calcium phosphate
Tricresyl phosphate
Widely used method for the conditioning of boiler feed water is the
Cold lime process
Coagulation
Hot-lime soda process
Sequestration
Phenol formaldehyde resin is used as an adhesive in making
Laminates
Card boxes
Furniture
Books
Bakelite is chemically known as
Polyvinyl chloride (PVC)
Polybutadiene
Phenol formaldehyde
Polyurethane
Catalytic oxidation of toluene produces
Styrene
Phenol
Benzene
Tri-nitro-toluene
The basic constituent of vegetable oils is
Triglyceride
Fatty acids
Fatty alcohol
Mono esters
Permanent hardness of water can be removed by
Simply boiling
Adding alum
Passing it through cation & anion exchangers
All (A), (B) and (C)
Sodium chloride content in sea water is about __________ gms/litre.
2
10
25
50
Which of the following is not responsible for causing permanent hardness of water?
Ca(HCO3)2
CaCl2
MgCl2
None of these
Pick out the wrong statement.
DDT is manufactured by the condensation of chlorobenzene with chloral at 30°C in presence of oleum, which is a highly exothermic reaction
Chloral is obtained by the chlorination of ethyl alcohol
Insecticides acting on the insects through the respiratory system are called fumigants
Benzene hexachloride is not a contact insecticide
The noble gas which occurs most abundantly in the atmosphere is
Helium
Neon
Krypton
Argon
Pure rectified spirit contains about __________ percent alcohol.
45
70
95
99.5
A 'unit process' is exemplified by the
Distillation
Hydrogenation of oils
Absorption
Humidification
Viscosity index improver (like polystyrene or polyisobutylene) is added to lubricant to
Reduce its viscosity
Increase its viscosity
Reduce the variation in its viscosity with temperature
Increase the variation in its viscosity with temperature
Massecuite is
Used for paper making
Used as a cattle feed
Highly acidic in nature
None of these
Low temperature carbonisation of coal takes place at __________ °C.
300
1100
700
900
Dense soda ash used in the manufacture of glass, is chemically represented by
Na2CO3
Na2CO3.10H2O
Na2CO3.H2O
Na2HCO3
Dichloro diphenyl __________ is the full form of DDT (an insecticide).
Tetrachloroethane
Trichloroethane
Tetrachloromethane
Trichloromethane
Which of the following is used as a coagulant in treating turbid water?
Chlorine
Ferric sulphate
Calcium sulphate
Activated carbon
Chrome tanning and vegetable tanning are done for
Light & heavy leather respectively
Heavy & light leather respectively
Both light & heavy leather
Neither light nor heavy leather