21. Which is the most ideal feed stock for ‘coking’ process used for the manufacture of petroleum coke ? September 7, 2025 by Admin Naphtha Vacuum residue Light gas oil Diesel ✅ The correct answer is option B.
22. A fuel oil consists of 4 fractions A, B, C and D. Their molar compositions and vapour pressures are given below : The vapour pressure of the fuel oil will be __________ mm Hg. September 7, 2025 by Admin 736 727.5 512 767.8 ✅ The correct answer is option A.
23. Catalytic cracking compared to thermal cracking of residue of vacuum distillation of crude oil September 7, 2025 by Admin gives higher yield of petrol. lower octane number of petrol. higher sulphur content in the product. higher gum forming material in petrol. ✅ The correct answer is option A.
24. H/C ratio (by weight) for the same number of carbon atoms is the highest in case of September 7, 2025 by Admin aromatics paraffins olefins naphthenes ✅ The correct answer is option D.
25. The general formula of naphthenes is September 7, 2025 by Admin CnH2n + 2 CnH2n-6 (where, n ≥ 6) CnHn-4 same as that for olefins i.e. CnH2n ✅ The correct answer is option D.
26. Smoke volatility index is equal to smoke point plus September 7, 2025 by Admin 0.42 x(% distilled at 204°C) 5 mm 0.84 x (% distilled at 204°C) 10 mm. approximately ✅ The correct answer is option A.
27. Main constituent of natural gas is September 7, 2025 by Admin CH4 C2H2 C2H4 C2H6 ✅ The correct answer is option A.
28. Iso-octane is used as a reference substance in the definition of octane number and it is assigned an octane number value of 100. Iso-octance is chemically known as September 7, 2025 by Admin α-methyl naphthalene. 2-2-4 tri methyl pentane. 1, 3 butadiene. tetra methyl ethylene. ✅ The correct answer is option B.
29. The most suitable solvent for deasphalting vacuum residue is September 7, 2025 by Admin propane methyl ethyl ketone doctor’s solution methanol amine ✅ The correct answer is option B.
30. __________ test is done to find out the softening point of bitumen. September 7, 2025 by Admin Impact Ball and ring Flame Viscosity ✅ The correct answer is option B.