491. Lime and soda ash are added to water to remove
Bicarbonates & sulphates of calcium and magnesium
Undersirable taste and odour
Bacteria
Its corrosiveness
✅ The correct answer is option A.
Chemical Process MCQs
492. Metallic soap (e.g. aluminium or calcium salts of fatty acids) can be used
As a lubricant
As a rust preventive
In hard water for cleaning of cloth
As a foam depressant in distillation column
✅ The correct answer is option A.
493. Trinitro-toluene (TNT) is
Used in glycerine manufacture
An explosive
Used in dye manufacture
None of these
✅ The correct answer is option B.
494. In contact process, SO₃ is absorbed in 97% H₂SO₄ and not in water, because
SO₃ gas is sparingly soluble in water
Water forms an acid mist, which is difficult to absorb
The purity of acid is affected
Scale formation in the absorber is to be avoided
✅ The correct answer is option B.
495. Teflon is
Phenol formaldehyde
An inorganic polymer
Poly tetrafluoroethylene (P.T.F.E.)
A monomer
✅ The correct answer is option C.
496. The yield of tar from high temperature carbonisation of dry coal is about __________ percent.
3
12
22
0.3
✅ The correct answer is option A.
497. Proximate analysis of coal determines its __________ content.
Moisture, ash, sulphur & volatile matter
Moisture & volatile matter
Moisture, sulphur, nitrogen & fixed carbon
None of these
✅ The correct answer is option B.
498. Deaeration of water in its treatment is necessary, as it
Minimises its turbidity
Helps in controlling its taste and odour
Minimises its corrosiveness
None of these
✅ The correct answer is option C.
499. Concentration of sulphide ores is done usually by
Roasting
Smelting
Froth floatation
Electro magnetic separation
✅ The correct answer is option C.
500. Which of the following is an explosive?
Nitroglycerene
Trintrotoluene (TNT)
Cellulose nitrate
All of the above
✅ The correct answer is option D.