411. Fire clay is __________ refractory material. A basic An acidic A neutral Not a ✅ The correct answer is option B.
412. Phosphate rock is a raw material for the manufacture of Phosphoric acid Phosphorous Superphosphates All of the above ✅ The correct answer is option D.
413. Oxidation of ortho-xylene in presence of __________ catalyst is done to produce phthalic anhydride on commercial scale. Nickel Vanadium Alumina Iron ✅ The correct answer is option B.
414. Neon gas is Flammable in nature Used in color discharge tube Filled in lamps having tungsten filament All of the above ✅ The correct answer is option B.
415. Platinum catalyst used in the earlier days of sulphuric acid manufacture by contact process suffers from the drawback like High cost Fragile nature Easy poisoning tendency All of the above ✅ The correct answer is option D.
416. Refractory bricks having high thermal conductivity is desirable, when it is to be used in the L.D. converter Blast furnace Rotary kiln Recuperator ✅ The correct answer is option D.
417. Main use of liquid nitrogen is in Rocket propulsion Making gun powder Detergent manufacture Refrigerative cooling ✅ The correct answer is option D.
418. The drug used in contraceptives is Sulphadizene Mestranol Methyl salicylate Pencillin ✅ The correct answer is option B.
419. Use of chlorine in the treatment of sewage Helps in grease separation Increases the biological oxygen demand(BOD) Causes bulking of activated sludge Aids in flocculation ✅ The correct answer is option A.
420. In the manufacture of sulphuric acid from elemental sulphur, the following sequence of major operations is followed : Furnace → converter → absorber Furnace → evaporator → absorber Furnace → converter → evaporator Converter → furnace → absorber ✅ The correct answer is option A.