The most commonly used substance to speed up the sedimentation of sewage is___________________?
(A) Lime
(B) Sulphuric acid
(C) Chlorine
(D) Sodium bisulphite
Which of the following is not produced commercially from sea water ?
(A) Magnesium & potassium compounds
(B) Common salt
(C) Bromine
(D) Iodine
Flexible foam (for mattresses) is usually made of_____________________?
(A) PVC
(B) Silicone
(C) Polyurethanes
(D) Polyamides
Thermoplastic materials_____________________?
(A) Do not soften on application of heat
(B) Are heavily branched molecules
(C) Are solvent insoluble
(D) None of these
The main aim behind cooling the digested chip at the bottom portion of the digestor by injecting cold black liquor is to___________________?
(A) Avoid mechanical weakening of fibre
(B) Remove lignin by way of crystallisation
(C) Increase the cellulose content
(D) None of these
Main product in calcium carbide-water reaction is___________________?
(A) Ca(OH)2
(B) C2H2
(C) CO2
(D) CaCO3
The yield of tar from high temperature carbonisation of dry coal is about _______________ percent?
(A) 3
(B) 12
(C) 22
(D) 0.3
Permanent hardness of water can be removed by____________________?
(A) Simply boiling
(B) Adding alum
(C) Passing it through cation & anion exchangers
(D) All (A),
Bitterns is a/an_________________?
(A) Unsaturated fat
(B) Starting material for the production of iodine
(C) By-product of chlor-alkali industry
(D) None of these
Nylon-66 is so named because the____________________?
(A) Average degree of polymerisation of the polymer is 1966
(B) Number of carbon atoms between two nitrogen atoms are 6
(C) Number of nitrogen atoms between two carbon atoms are 6
(D) Polymer was first synthesised in 1966