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

1 Answer

Answer :

(D) Greater depth of cracking gives lower octane number gasoline

Related questions

Description : 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 ... with increase in the catalyst to oil ratio (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Though increased pressure has a retarding effect on cracking reaction, yet in actual process, a positive pressure of 10-15 kgf/cm2 is maintained during cracking mainly to (A) Increase the yield of ... coke formation (C) Enhance the octane number of gasoline (D) Reduce gum content in gasoline

Last Answer : (B) Suppress coke formation

Description : Catalytic cracking compared to thermal cracking of residue of vacuum distillation of crude oil (A) Gives higher yield of petrol (B) Lower octane number of petrol (C) Higher sulphur content in the product (D) Higher gum forming material in petro

Last Answer : (A) Gives higher yield of petrol

Description : In catalytic cracking, the (A) Gasoline obtained has a very low octane number (B) Pressure & temperature is very high (C) Gasoline obtained has very high aromatic content (D) Gasoline obtained has very high amount of gum forming compounds

Last Answer : (C) Gasoline obtained has very high aromatic content

Description : Paraffin base crude oil as compared to asphalt base crude gives (A) Higher yield of straight run gasoline (B) Higher octane number gasoline (C) Lower viscosity index lube oil (D) Poorer yield of lube oil

Last Answer : (A) Higher yield of straight run gasoline

Description : Straight run naphtha is converted into high octane number petrol (gasoline) by catalytic (A) Cracking (B) Polymerisation (C) Reforming (D) Isomerisation

Last Answer : (C) Reforming

Description : Octane number of gasoline produced by two stage fluidised catalytic cracking process is (A) 80 (B) 87 (C) 92 (D) 97

Last Answer : (D) 97

Description : When petroleum is refined it is subject to a number of processes including cracking. During the cracking process w) lighter hydrocarbons are combined to form heavier ones x) heavy hydrocarbons ... lighter hydrocarbons are separated by distillation z) oxygen is used to burn the heavier hydrocarbons

Last Answer : ANSWER: X -- HEAVY HYDROCARBONS ARE BROKEN UP INTO LIGHTER ONES

Description : Octane number of gasoline is obtained by comparing the performance of the engine when running on a mixture of the following hydrocarbons A. ethane and methane B. normal heptane and iso-octane C. iso-heptane and octane D. iso-octane and TEL

Last Answer : ANSWER : B

Description : Pick out the wrong statement. (A) Higher temperature is employed in visbreaking than in thermal cracking (B) Pyrolysis is a mild thermal cracking process (C) Lead susceptibility of ... Operating pressure and temperature in thermal cracking process is more than that in catalytic cracking process

Last Answer : (A) Higher temperature is employed in visbreaking than in thermal cracking (B) Pyrolysis is a mild thermal cracking process

Description : Which of the following methods can be used to increase the octane rating of gasoline? (a) Adding branched-chain alkanes (b) Adding tetraethyllead (c) Adding aromatic hydrocarbons (d) All of these

Last Answer : All of these

Description : Which of the following statements are true of the multiple organ dysfunction syndrome (MODS)? A. The two-hit model proposes that secondary MODS may be produced when even a relatively ... intensive care units has decreased owing to increased awareness, prevention, and treatment of the syndrome.

Last Answer : Answer: ABC DISCUSSION: MODS is part of a clinical continuum that begins with the systemic inflammatory response syndrome, which is the host's stress response to any major insult such ... pathogenesis of MODS, the incidence of MODS continues to increase without a significant improvement in outcome

Description : For absorbers, high pressure drop results in (A) Increased efficiency (B) Decreased efficiency (C) High operating cost (D) Better gas liquid contact

Last Answer : (C) High operating cost

Description : An increase in the NH3 /CO2 ratio in urea manufacture results in (A) Increased degree of conversion of CO2 to urea (B) Decreased degree of conversion of NH3 to urea (C) Decreased yield of urea (D) Decreased specific volume of molten mass

Last Answer : (A) Increased degree of conversion of CO2 to urea

Description : Pick out the wrong statement. (A) Higher specific gravity of petroleum products means higher C/H ratio (B) Aromatics have lower specific gravity than corresponding paraffins (C) Hydrocarbons of low ... of high specific gravity (e.g., aromatics) possess the maximum thermal energy per unit weight

Last Answer : (B) Aromatics have lower specific gravity than corresponding paraffins

Description : __________ of a material results, when its strength is increased & ductility is decreased by heating at a relatively lower temperature after cold working. (A) Solid solution hardening (B) Screw dislocation (C) Strain ageing (D) Twinning

Last Answer : (C) Strain ageing

Description : Pick out the wrong statement. (A) Alkylation produces a larger iso-paraffin (having higher octane number) from the reaction of an olefin with smaller iso-paraffin (B) Catalytic alkylation processes use HF ... (> 1000°C) (D) Gasoline having an octane number of 90 can be produced by alkylation process

Last Answer : (C) All the alkylation processes use very high temperature (> 1000°C)

Description : 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 ... atoms (D) The aromatics have lower octane number than naphthenes with same number of carbon atoms

Last Answer : (A) Octane number of i-octane is zero

Description : Power alcohol as compared to straight run gasoline has lower (A) Calorific value (B) Octane number (C) Specific gravity (D) Viscosity

Last Answer : (A) Calorific value

Description : Pick out the wrong statement. (A) Lower boiling paraffins have higher octane number than higher paraffins (B) Dehydrogenation of naphthenes to aromatics is a desirable reaction in reforming ... is dearomatised kerosene (D) Catalyst used in catalytic reforming is platinum on silica-alumina base

Last Answer : (C) The most ideal feedstock for thermal reforming is dearomatised kerosene

Description : Sepsis causes a marked metabolic response. Which of the following statement(s) is/are true concerning the metabolic response to sepsis? a. Oxygen consumption is increased in the face of infection ... d. The extent of increase in oxygen consumption relates to the severity of the infection

Last Answer : Answer: a, c, d Oxygen consumption is usually elevated in the infected patient. The extent of this increase is related to the severity of the infection, with peak elevations reaching 50% ... suggest that the metabolic rate increases 10% to 13% for each elevation of 1°C in central temperature

Description : For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in (A) Increased economy (B) Decreased economy (C) Lower capacity (D) No effect on economy

Last Answer : (A) Increased economy

Description : Prophylactic therapy of migraine: A. Is recommended in all cases B. Benefits upto 70% patients of moderate to severe migraine C. Needs to be continued lifelong without interruption D. Reduces the severity but increases the frequency of migraine attacks

Last Answer : B. Benefits upto 70% patients of moderate to severe migraine

Description : __________ determination is not a very significant and important test for gasoline. (A) Gum & sulphur content (B) Viscosity (C) Octane number (D) Reid vapor pressure

Last Answer : (B) Viscosity

Description : Higher pressure in the reforming reactor (A) Increases coke formation (B) Increases the rate of reaction (C) Produces high octane number gasoline (D) None of these

Last Answer : (D) None of these

Description : Octane number of gasoline is a measure of its (A) Resistance to knock (B) Ignition delay (C) Ignition temperature (D) Smoke point

Last Answer : (A) Resistance to knock

Description : Choose the correct statement about severity of side effects to oral iron medication: A. Ferrous salts are better tolerated than ferric salts B. Complex organic salts of iron are better ... better tolerated than tablets D. Tolerability depends on the quantity of elemental iron in the medication

Last Answer : D. Tolerability depends on the quantity of elemental iron in the medication

Description : Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence ... D) Half life of a reaction increases with increased initial concentration for reaction orders more than one

Last Answer : (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same

Description : Pick out the wrong statement regarding the solubility characteristics of high polymers. (A) Greater the degree of cross-linking in the polymer, lesser is its solubility (B) Polymers having more ... of the solvent (D) High molecular weight polymers on dissolving gives solution of very low viscosity

Last Answer : (D) High molecular weight polymers on dissolving gives solution of very low viscosity

Description : In an incompressible fluid, the density is (A) Greatly affected by moderate changes in pressure (B) Greatly affected only by moderate changes in temperature (C) Not affected with moderate change in temperature & pressure (D) Sensible to changes in both temperature & pressure

Last Answer : (C) Not affected with moderate change in temperature & pressure

Description : Liquid hydrocarbons are converted to low molecular weight gaseous hydrocarbons by a process known as (a) hydrogenation (b) reforming (c) cracking (d) reduction

Last Answer : Ans:(c)

Description : Aromatics have the highest __________ of all the hydrocarbons of same carbon atoms. (A) Smoke point (B) Octane number (C) Cetane number (D) Viscosity

Last Answer : (B) Octane number

Description : Higher boiling fractions like atmospheric residue is distilled under vacuum at low temperature because at high temperature, there is a tendency of the predominance of (A) Thermal cracking (B) Gum formation (C) Coking (D) Discoloration

Last Answer : (C) Coking

Description : Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop

Last Answer : (A) Decreased capacity

Description : Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Last Answer : (A) Increased COP

Description : Pick out the correct statement. (A) Paraffins have higher octane number than corresponding iso-paraffin (B) Paraffins have lower smoke point than aromatics

Last Answer : (B) Paraffins have lower smoke point than aromatics

Description : Assertion A: For a given depth of cut, the output of a power shovel can be increased by decreasing the angle of swing. Reason R: If the angle of swing is decreased, the cycle time will be decreased. Select the ... explanation of A (C) A is true but R is false (D) A is false but R is true

Last Answer : (A) Both A and R is true and R is the correct explanation of A

Description : The colour of gasoline is an indication of its (A) Octane number (B) Lead susceptibility (C) Gum forming tendency & thoroughness of refining (D) None of these

Last Answer : (C) Gum forming tendency & thoroughness of refining

Description : Phenols are added in gasoline to (A) Improve the octane number (B) Act as an antioxidant (C) Reduce its viscosity (D) Increase its pour point

Last Answer : (B) Act as an antioxidant

Description : Octane number (unleaded) of reformed gasoline may be upto (A) 60 (B) 70 (C) 80 (D) 90

Last Answer : (D) 90

Description : The octane number of aviation gasoline may be (A) 79 (B) 87 (C) 97 (D) > 100

Last Answer : (D) > 100

Description : Which of the following gasoline (unleaded) has the least octane number? (A) Catalytically cracked gasoline (B) Straight run gasoline (C) Catalytically reformed gasoline (D) Polymer gasoline

Last Answer : (B) Straight run gasoline

Description : Octane number (unleaded) of gasoline produced by isomerisation of butane may be about (A) 45 (B) 55 (C) 70 (D) 90

Last Answer : (C) 70

Description : The amount of tetraethyl lead added to improve the octane number of motor gasoline is around __________ c.c per gallon of petrol. (A) 3 (B) 300 (C) 3000 (D) 1000

Last Answer : (A) 3

Description : In petroleum refining, the process used for conversion of hydrocarbons to aromatics is (A) Catalytic cracking (B) Catalytic reforming (C) Hydrotreating (D) Alkylation

Last Answer : (B) Catalytic reforming

Description : Sometimes water is sprayed during coal charging in the coke oven, which helps in (A) Prevention of clinker formation in the oven (B) Controlling the dust nuisance while charging the coal (C) Reducing the cracking of hydrocarbons in ... represented by C + H2O = CO + H2 ) (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : In any fuel, the percentage by volume of isooctane in a mixture of isooctane and n-heptane which will knock under same conditions as the fuel being tested, is called : (a) Cracking (b) Iodine number (c) Aromatization (d) Octane number

Last Answer : Octane number

Description : Octane numbers of motor gasoline used in India and America are respectively (A) 87 & 94 (B) 94 & 87 (C) 94 & 100 (D) 83 & 100

Last Answer : (A) 87 & 94

Description : Visbreaking process is used mainly for making (A) High cetane diesel (B) High octane gasoline (C) Fuel oil (D) Smoke free kerosene

Last Answer : (C) Fuel oil

Description : Tetra-ethyl lead is added in gasoline to (A) Increase its smoke point (B) Reduce gum formation (C) Reduce the pour point (D) Increase its octane numbe

Last Answer : (D) Increase its octane numbe