Chemical Engineering Mcqs

Pick out the correct statement pertaining to catalytic cracking ?
  • (A)  With increase in the reactor pressure, octane number of gasoline decreases
  • (B)  With increase in the reactor temperature, gasoline yield decreases for a given conversion
  • (C)  Percentage conversion increases with increase in the catalyst to oil ratio
  • (D)  All
Choose the correct statement regarding thermal cracking ?
  • (A)  Moderate changes in operating temperature does not change the depth of cracking
  • (B)  Increased residence time results in the decreased severity of cracking
  • (C)  At low pressure, the yield of lighter hydrocarbons are more
  • (D)  Greater depth of cracking gives lower octane number gasoline
Pick out the wrong statement ?
  • (A)  Iso-paraffin crack faster than n-paraffin.
  • (B)  Catalytic cracking is endothermic, but the regeneration of catalyst is exothermic
  • (C)  Rate of decomposition of olefins in catalytic cracking is slightly slower than the thermal cracking
  • (D)  None of these
Pick out the wrong statement ?
  • (A)  Pensky-Marten apparatus is used for determining flash points above 50°C
  • (B)  Characterisation factor of paraffinic crude oil is more than 12
  • (C)  Abel apparatus is used for determining flash points below 50°C
  • (D)  An oil having high susceptibility to change in viscosity with temperature changes, has a high viscosity index
Pick out the wrong statement?
  • (A)  Aromatics have higher specific gravity than paraffins
  • (B)  Gross calorific value (GCV) of petrofuels is equal to (12400 – 2100 ρ2) where, ρ is the specific gravity of the fuel at 15.5°C
  • (C)  Heavier petrofuels have higher GCV on weight basis (i.e., Kcal/kg) but lower GCV on volume basis (i.e., Kcal/litre)
  • (D)  Higher specific gravity of petrofuels means higher C/H ratio
Choose the correct statement ?
  • (A)  Octane number of i-octane is zero
  • (B)  Octane number of paraffins increases with increasing number of carbon atoms
  • (C)  Branched chain paraffins have higher octane number than straight chain paraffins with same number of carbon atoms
  • (D)  The aromatics have lower octane number than naphthenes with same number of carbon atoms
Choose the correct statement?
  • (A)  Coking tendency increases with increasing molecular weight
  • (B)  Coking tendency decreases with increasing molecular weight
  • (C)  Higher pressure enhances coke formation
  • (D)  Coking is an exothermic reaction
Pick out the correct statement?
  • (A)  Paraffins have higher octane number than corresponding iso-paraffin
  • (B)  Paraffins have lower smoke point than aromatics
  • (C)  Suitability of kerosene as a fuel & as an illuminant may be determined by char value test
  • (D)  Aviation fuel should have very high cloud point
Pick out the wrong statement?
  • (A)  Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition
  • (B)  Alumina is added as a promoter to iron catalyst in ammonia synthesis reaction
  • (C)  Activation energy for a reaction is obtained from the intercept of the Arrhenius plot
  • (D)  Presence of inerts affects the equilibrium conversion of
Pick out the wrong statement?
  • (A)  A particular chemical reaction is more temperature sensitive at low temperatures
  • (B)  A very high value of equilibrium constant, K (K >> 1) indicates that the reaction is practically irreversible in nature
  • (C)  The intercept of the Arrhenius plot is called the ‘activation energy’
  • (D)  Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions