51. When a suitable fraction from petroleum distillation (C12 and higher) is heated at high temperature (500°𝐶) in the presence of a catalyst the molecule break apart and rearrange to smaller, more highly branched alkanes having 5-10 carbon atoms. This process is called as:

(a) Thermal cracking
(b) Catalytic cracking
(c) Octane rating
(d) Knocking

Answer: (b)

52. High speed engines require:
(a) Same octane value fuel
(b) High octane value fuel
(c) Low octane value fuel
(d) Average octane value fuel

Answer: (c)

53. Which one of the following will act as a catalyst for selectoforming (a mild hydrogeneration process) in petroleum refining?
(a) Non-metals
(b) Non-noble metals
(c) Noble metals
(d) Transition metals

Answer: (b)

54. Hydrocracking is a process of cracking in the presence of:
(a) Water
(b) Hydrogen
(c) Hydroxide
(d) Hydrides

Answer: (b)

55. Propane has a heat of vaporization of 101.8 cal/g at −42.1°𝐶, and its critical constant is 96.7°𝐶. The heat of vaporization at 80°𝐶 will be:
(a) 50.4 cal /𝑔
(b) 45.6 cal /𝑔
(c) 40.4 cal/𝑔
(d) 35.6 cal/𝑔

Answer: (b)

56. Graphite is being used for rocket nozzles, and wing leading edges and nose cones of reentry vessels because of its:
(a) Light weight and good mechanical strength at extremely high temperature
(b) Use with practically all mineral acids, salts solutions, alkalies and organic compounds
(c) Easy machining qualities, together with its availability in many size and shapes
(d) High thermal conductivity

Answer: (a)

57. Catalytic cracking is the most widely used refinery process for converting:
(a) Light oils into gasoline of high octane value
(b) Light oils into gasoline of low octane value
(c) Heavy oils into gasoline of high octane value
(d) Heavy oils into gasoline of low octane value

Answer: (c)

58. H-Oil process is used for:
(a) Desulphurizing and demetallising residua as well as produce low sulfur cat cracker feed stocks
(b) Desulphurizing and metallising residua as well as produce low sulfur cat cracker feed stocks
(c) Sulphurizing and metallising residua as well as produce low sulfur cat cracker feed stocks
(d) Desulphurizing and demetallising residua as well as produce high sulfur cat cracker feed stocks

Answer: (a)

59. Pure, strong phosphoric acid is manufactured from elementary phosphorous by:
(a) Oxidation and hydration
(b) Oxidation and dehydration
(c) Oxidation, reduction and hydration
(d) Oxidation and hydroxylation

Answer: (a)

60. Aniline point of Diesel fuel is defined as:
(a) The maximum temperature at which equal volumes of anhydrous aniline and oil mix together
(b) The maximum temperature at which unequal volumes of anhydrous aniline and oil mix together
(c) The minimum temperature at which equal volumes of anhydrous aniline and oil mix together
(d) The minimum temperature at which unequal volumes of anhydrous aniline and oil mix together

Answer: (d)