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

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
by

1 Answer

Answer :

(C) Coking
by

Related questions

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

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

Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if distilled directly at atmospheric pressure (C) Material cannot be distilled by indirect heating even under low pressure, because of the high boiling temperature (D) Material to be distilled is thermally unstable or has the tendency to react with other components associated with it, at the boiling temperature

Description : Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if ... unstable or has the tendency to react with other components associated with it, at the boiling temperature

Last Answer : (A) Azeotropic mixture is to be separated and the final product is miscible with water

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

Description : 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

Last Answer : (A) Coking tendency increases with increasing molecular weigh

Which is the most ideal feed stock for 'coking' process used for the manufacture of petroleum coke? (A) Naphtha (B) Vacuum residue (C) Light gas oil (D) Diesel

Description : Which is the most ideal feed stock for 'coking' process used for the manufacture of petroleum coke? (A) Naphtha (B) Vacuum residue (C) Light gas oil (D) Diesel

Last Answer : (B) Vacuum residue

Which of the following fractions of petroleum contains maximum sulphur? (A) Diesel (B) Gasoline (C) Naphtha (D) Atmospheric residue

Description : Which of the following fractions of petroleum contains maximum sulphur? (A) Diesel (B) Gasoline (C) Naphtha (D) Atmospheric residue

Last Answer : (D) Atmospheric residue

Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low boiling products are prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Description : Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low ... prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Last Answer : (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose

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

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

Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these

Description : Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these

Last Answer : (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls

The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the (A) Solution has an elevation of boiling point (B) Evaporators operate under vacuum (C) Evaporators operate at atmospheric pressure (D) None of these

Description : The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the (A) Solution has ... B) Evaporators operate under vacuum (C) Evaporators operate at atmospheric pressure (D) None of these

Last Answer : (A) Solution has an elevation of boiling point

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 light distillates (B) Suppress coke formation (C) Enhance the octane number of gasoline (D) Reduce gum content in gasoline

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

Which of the following fractions of a crude oil will have the maximum gravity API (i.e. °API)? (A) Diesel (B) Gasoline (C) Atmospheric gas oil (D) Vacuum gas oil

Description : Which of the following fractions of a crude oil will have the maximum gravity API (i.e. °API)? (A) Diesel (B) Gasoline (C) Atmospheric gas oil (D) Vacuum gas oil

Last Answer : (C) Atmospheric gas oil

Softening temperature of coal ash is a measure of the __________ of coal. (A) Caking tendency (B) Coking tendency (C) Clinkering tendency (D) Size stability

Description : Softening temperature of coal ash is a measure of the __________ of coal. (A) Caking tendency (B) Coking tendency (C) Clinkering tendency (D) Size stability

Last Answer : (C) Clinkering tendency

The boiling point of water decreases at higher altitudes is due to – (1) low temperature (2) low atmospheric pressure (3) high temperature (4) high atmospheric pressure

Description : The boiling point of water decreases at higher altitudes is due to – (1) low temperature (2) low atmospheric pressure (3) high temperature (4) high atmospheric pressure

Last Answer : (2) low atmospheric pressure Explanation: At higher altitudes, the air pressure is decreased, which forces water's boiling point to lower. The air pressure decreases with altitude because of the ... of air. The lowered boiling point of water requires an increase in cooking times or temperature.

The boiling point of water decreases at higher altitudes is due to (1) low temperature (2) low atmospheric pressure (3) high temprature (4) high atmospheric pressure

Description : The boiling point of water decreases at higher altitudes is due to (1) low temperature (2) low atmospheric pressure (3) high temprature (4) high atmospheric pressure

Last Answer : low atmospheric pressure

Mineral oils (e.g. petroleum oils) are preferred over fatty oils (e.g. mustard oil, ghee, tallow, palm oil, olive oil etc.) as a lubricant due to its (A) Poor oxidation stability and high gum forming tendency (B) Greater tendency of decomposition at elevated temperature (C) Hydrolysis tendency in presence of water (D) All (A), (B) and (C)

Description : Mineral oils (e.g. petroleum oils) are preferred over fatty oils (e.g. mustard oil, ghee, tallow, palm oil, olive oil etc.) as a lubricant due to its (A) Poor oxidation stability and high gum forming ... at elevated temperature (C) Hydrolysis tendency in presence of water (D) All (A), (B) and (C)

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

Boiling point of water gets lowered at high altitudes (e.g., hills), because (A) Temperature is low (B) Atmospheric pressure is low (C) Atmospheric pressure is high (D) None of these

Description : Boiling point of water gets lowered at high altitudes (e.g., hills), because (A) Temperature is low (B) Atmospheric pressure is low (C) Atmospheric pressure is high (D) None of these

Last Answer : Option B

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 petrol produced by catalytic process is more than that produced by thermal cracking (D) Operating pressure and temperature in thermal cracking process is more than that in catalytic cracking process

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

Asphalts are(A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Description : Asphalts are (A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Last Answer : (C) Readily oxidisable and form carbonaceous sludge

Petroleum coke is commercially produced by the __________ process. (A) Hydrocracking (B) Visbreaking (C) Fluid catalytic cracking (D) Delayed coking

Description : Petroleum coke is commercially produced by the __________ process. (A) Hydrocracking (B) Visbreaking (C) Fluid catalytic cracking (D) Delayed coking

Last Answer : (D) Delayed coking

Which of the following processes in oil refinery does not employ ‘cracking’? (A) Coking (B) Visbreaking (C) Pyrolysis (D) None of these

Description : Which of the following processes in oil refinery does not employ ‘cracking’? (A) Coking (B) Visbreaking (C) Pyrolysis (D) None of these

Last Answer : (D) None of these

Stainless steel is welded with difficulty because of (A) Its high melting temperature (B) Chances of cracking (C) Oxide film formation (D) Chromium carbide formation

Description : Stainless steel is welded with difficulty because of (A) Its high melting temperature (B) Chances of cracking (C) Oxide film formation (D) Chromium carbide formation

Last Answer : Option C

Reid vapour pressure of gasoline is the measure of its (A) Pour point (B) Cloud point (C) Vapour locking tendency (D) Carbon residue

Description : Reid vapour pressure of gasoline is the measure of its (A) Pour point (B) Cloud point (C) Vapour locking tendency (D) Carbon residue

Last Answer : (C) Vapour locking tendency

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

Description : 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 ... of lighter hydrocarbons are more (D) Greater depth of cracking gives lower octane number gasoline

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

In Lurgi coal gasifier, (A) Coking coals cannot be used (B) Low carbon conversion efficiency is achieved (C) Entrainment of solids is higher (D) Larger quantity of coal can be processed

Description : In Lurgi coal gasifier, (A) Coking coals cannot be used (B) Low carbon conversion efficiency is achieved (C) Entrainment of solids is higher (D) Larger quantity of coal can be processed

Last Answer : (D) Larger quantity of coal can be processed

In the Lurgi coal gasifier (A) Coking coals cannot be used (B) Low carbon conversion efficiency is achieved (C) Entrainment of solids is higher (D) Large quantity of coal can be processed

Description : In the Lurgi coal gasifier (A) Coking coals cannot be used (B) Low carbon conversion efficiency is achieved (C) Entrainment of solids is higher (D) Large quantity of coal can be processed

Last Answer : (D) Large quantity of coal can be processed

The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and recondensed, and so on until all the available liquid fuels are separately recovered in the sequence of their boiling points. Such a process is called  A. cracking  B. carbonisation  C. fractional distillation  D. full distillation

Description : The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and ... is called  A. cracking  B. carbonisation  C. fractional distillation  D. full distillation

Last Answer : Answer: C

Gum formation in stored gasoline is mainly due to the (A) Alkylation of unsaturated (B) Presence of sulphur (C) Oxidation & polymerisation of unsaturated (D) Higher aromatic content

Description : Gum formation in stored gasoline is mainly due to the (A) Alkylation of unsaturated (B) Presence of sulphur (C) Oxidation & polymerisation of unsaturated (D) Higher aromatic content

Last Answer : (B) Presence of sulphur

When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation. (A) Continuous (B) Steam (C) Azeotropic (D) None of these

Description : When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation. (A) Continuous (B) Steam (C) Azeotropic (D) None of these

Last Answer : (B) Steam

Which of the following has the highest gum forming tendency in gosoline? (A) Paraffins (B) Diolefins (C) Aromatics (D) Naphthenes

Description : Which of the following has the highest gum forming tendency in gosoline? (A) Paraffins (B) Diolefins (C) Aromatics (D) Naphthenes

Last Answer : (B) Diolefins

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

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

At high altitudes it is difficult to cook eggs or vegetables properly because of (a) High boiling point of water and low atmospheric pressure (b) Low boiling point of water and low atmospheric pressure (c) Low value of acceleration due to gravity (d) High atmospheric pressure and low billing point of water

Description : At high altitudes it is difficult to cook eggs or vegetables properly because of (a) High boiling point of water and low atmospheric pressure (b) Low boiling point of water and low atmospheric ... Low value of acceleration due to gravity (d) High atmospheric pressure and low billing point of water

Last Answer : Ans:(b)

Cold cracking in the heat affected zone of a high strength steel weld can take place because of the (A) Retained austenite (B) Martensite formation (C) Relatively high sulphur content in the base metal (D) Sufficient hydrogen present in the welding arc

Description : Cold cracking in the heat affected zone of a high strength steel weld can take place because of the (A) Retained austenite (B) Martensite formation (C) Relatively high sulphur content in the base metal (D) Sufficient hydrogen present in the welding arc

Last Answer : (B) Martensite formation

A liquid with high boiling point decomposes on simple distillation but it can be steam distilled for its purification .Explain how is it possible?

Description : A liquid with high boiling point decomposes on simple distillation but it can be steam distilled for its purification .Explain how is it possible?

Last Answer : In steam distillation boiling occurs when vapour pressure of organic compound & steam becomes equal to atmospheric pressure. As vapour pressure of water is higher than the organic liquid. ... organic liquid vaporizes at a temperature below its boiling point in steam distillation without decomposing.

Which of the following fuels is generally not used in thermal power plant boiler firing? (A) Furnace oil, light diesel oil and tar/PCM (B) Pulverised coking coal (C) Coal middling from washeries (D) B.F. gas, coke oven gas and L.D. converter gas

Description : Which of the following fuels is generally not used in thermal power plant boiler firing? (A) Furnace oil, light diesel oil and tar/PCM (B) Pulverised coking coal (C) Coal middling from washeries (D) B.F. gas, coke oven gas and L.D. converter gas

Last Answer : (B) Pulverised coking coal

Road grade bitumen is produced from vacuum residue by its (A) Aeration (B) Pyrolysis (C) Hydrogenation (D) Steam reforming

Description : Road grade bitumen is produced from vacuum residue by its (A) Aeration (B) Pyrolysis (C) Hydrogenation (D) Steam reforming

Last Answer : (D) Steam reforming

The most suitable solvent for deasphalting vacuum residue is (A) Propane (B) Methyl ethyl ketone (C) Doctor's solution (D) Methanol amine

Description : The most suitable solvent for deasphalting vacuum residue is (A) Propane (B) Methyl ethyl ketone (C) Doctor's solution (D) Methanol amine

Last Answer : (B) Methyl ethyl ketone

Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure. Nitrobenzene will distil off __________ °C. (A) At < 100 (B) At > 210.6 (C) Between 100 and 210 (D) None of these

Description : Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure. Nitrobenzene will distil off __________ °C. (A) At < 100 (B) At > 210.6 (C) Between 100 and 210 (D) None of these

Last Answer : (A) At < 100

Which among the following is not a feature of village? A. Less population B. Less diversity C. Impersonal relationship D. Predominance of primary occupation

Description : Which among the following is not a feature of village? A. Less population B. Less diversity C. Impersonal relationship D. Predominance of primary occupation

Last Answer : C. Impersonal relationship

Which of the following is the most suitable feed for platforming process (reforming)? (A) Olefinic hydrocarbon (B) Naphtha (C) Fuel oil (D) Atmospheric residue

Description : Which of the following is the most suitable feed for platforming process (reforming)? (A) Olefinic hydrocarbon (B) Naphtha (C) Fuel oil (D) Atmospheric residue

Last Answer : (A) Olefinic hydrocarbon

Flash point of atmospheric distillation residue is determined by __________ apparatus. (A) Pensky-Martens (closed cup type) (B) Abel (C) Cleveland (open cup type) (D) None of these

Description : Flash point of atmospheric distillation residue is determined by __________ apparatus. (A) Pensky-Martens (closed cup type) (B) Abel (C) Cleveland (open cup type) (D) None of these

Last Answer : (C) Cleveland (open cup type)

Pick out the wrong statement. (A) Bubble size increases with the dynamic viscosity of the liquid in case of nucleate pool boiling (B) Thermal conductivity of a dry material is more than that of the damp material (C) Ratio of its capacity to economy equals the steam consumption in kg/hr in an evaporator (D) Vaporisation of organic substances in evaporator mostly causes foam formation

Description : Pick out the wrong statement. (A) Bubble size increases with the dynamic viscosity of the liquid in case of nucleate pool boiling (B) Thermal conductivity of a dry material is more than ... in kg/hr in an evaporator (D) Vaporisation of organic substances in evaporator mostly causes foam formation

Last Answer : (B) Thermal conductivity of a dry material is more than that of the damp material

Pressure Cooker cooks faster because (1) boiling point decreases with rise of pressure (2) it cooks the food at low pressure (3) higher temperature is attained for cooking (4) the material of the cooker is a good conductor

Description : Pressure Cooker cooks faster because (1) boiling point decreases with rise of pressure (2) it cooks the food at low pressure (3) higher temperature is attained for cooking (4) the material of the cooker is a good conductor

Last Answer : (3) higher temperature is attained for cooking Explanation: In pressure cooker boiling point of water increases due to high pressure.

Pressure Cooker cooks faster because (1) boiling point decreases with rise of pressure (2) it cooks the food at low pressure (3) higher temperature is attained for cooking (4) the material of the cooker is a good conductor

Description : Pressure Cooker cooks faster because (1) boiling point decreases with rise of pressure (2) it cooks the food at low pressure (3) higher temperature is attained for cooking (4) the material of the cooker is a good conductor

Last Answer : higher temperature is attained for cooking 

Presence of high concentration of ozone and smog in atmospheric air causes the(A) Embrittlement & decrease of folding resistance of paper(B) Cracking of rubber products(C) Fading of dye on textiles(D) Damage of electrical insulator on high tension power line

Description : Presence of high concentration of ozone and smog in atmospheric air causes the (A) Embrittlement & decrease of folding resistance of paper (B) Cracking of rubber products (C) Fading of dye on textiles (D) Damage of electrical insulator on high tension power line

Last Answer : (B) Cracking of rubber products

Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

Description : Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

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

Which of the following accentuates clinkering trouble on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportions of iron & sulphur (B) Low forced draught and fuel bed temperature (C) Thick fire bed and preheated primary air (D) All (A), (B) and (C)

Description : Which of the following accentuates clinkering trouble on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportions of iron & sulphur (B) Low forced draught and fuel bed temperature (C) Thick fire bed and preheated primary air (D) All (A), (B) and (C)

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

The proper arrangement of the petroleum fractions in order of their boiling points is (A) Lubricating oil > diesel > petrol > LPG (B) Lubricating oil > petrol > diesel > LPG (C) Petrol > lubricating oil > diesel > LPG (D) Petrol > diesel > LPG > lubricating oil

Description : The proper arrangement of the petroleum fractions in order of their boiling points is (A) Lubricating oil > diesel > petrol > LPG (B) Lubricating oil > petrol > diesel > LPG (C) Petrol > lubricating oil > diesel > LPG (D) Petrol > diesel > LPG > lubricating oil

Last Answer : (A) Lubricating oil > diesel > petrol > LPG

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 process (C) The most ideal feedstock for thermal reforming is dearomatised kerosene (D) Catalyst used in catalytic reforming is platinum on silica-alumina base

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

Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation (B) Cavitation may be caused due to boiling of liquid by decreasing the pressure resulting in formation & collapse of vapor cavities (C) Cavitation begins at higher static pressure and lower velocity in larger diameter pipelines resulting in audible noise(D) Large scale cavitation cannot damage pipeline, restrict fluid flow anddamage steam turbine blades

Description : Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation ... (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

Last Answer : (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades