What do you mean by pyrolysis?

What do you mean by pyrolysis?
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Answer :

The decomposition of a compound by the heat is called pyrolysis. This process when applied to alkanes is known as cracking.
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Related questions

Explain the physical properties of benzene and its homologues.

Description : Explain the physical properties of benzene and its homologues.

Last Answer : Ans: i. Benzene and its homologous upto eight carbon atoms are colourless liquids with characteristic smell. ii. Aromatic hydrocarbons are immiscible with water but soluble in organic solvents. iii. ... compounds increases with increase in molecular mass due to increase in van der waals forces.

Out of benzene, m–dinitrobenzene and toluene which will undergo nitration most easily and why?

Description : Out of benzene, m–dinitrobenzene and toluene which will undergo nitration most easily and why?

Last Answer : Ans. -CH3 group is electron donating while –NO2 group is electron withdrawing. Therefore, maximum electron density will be in toluene , followed by benzene and at least in m-dinitrobenzene. Therefore, the ease of nitration decreases in the order: Toluene> benzene> m-dinitrobenzene

Which one is more stable structure of benzene among Kekule and Dewar’s structures?

Description : Which one is more stable structure of benzene among Kekule and Dewar’s structures?

Last Answer : Ans: Kekule’s structure.

Define benzenoids Compounds.

Description : Define benzenoids Compounds.

Last Answer : Ans: Aromatic compounds containing benzene ring.

Define Aromatic Compounds.

Description : Define Aromatic Compounds.

Last Answer : Ans: The Compounds which gives pleasant smell.

What are alkanes? Why are they called paraffins?

Description : What are alkanes? Why are they called paraffins?

Last Answer : Ans. Those hydrocarbons which contain single bond between carbon- carbon are called alkanes. They are called paraffins because they are very less reactive (Latin- Parum= little, affins = affinity)

How will you separate propene from propyne?

Description : How will you separate propene from propyne?

Last Answer : Ans. By passing the mixture through ammonical silver nitrate solution when propyne reacts while propene passes over.

How will you demonstrate that double bonds of benzene are somewhat different from that of olefins?

Description : How will you demonstrate that double bonds of benzene are somewhat different from that of olefins?

Last Answer : Ans. The double bonds of olefins decolorize bromine water and discharge the pink colour of Bayer‘s reagent while those of benzene not.

What is Grignard reagent?

Description : What is Grignard reagent?

Last Answer : Ans. Alkyl magnesium halides

What is meant by restricted rotation around of carbon-carbon double bond? What type of isomerism does it lead to?

Description : What is meant by restricted rotation around of carbon-carbon double bond? What type of isomerism does it lead to?

Last Answer : Ans. The carbon-carbon double bond in alkene contains one sigma bond and one pi-bond. The Pibond involves the overlapping of unhybridised p orbital of two carbon atom .The rotation around the ... , the free rotation around C=C double bond is restricted, which gives rise to Geometrical Isomerism.

How will you detect the presence of unsaturation in an organic compound?

Description : How will you detect the presence of unsaturation in an organic compound?

Last Answer : Ans. Generally Unsaturated organic compound decolorize Bayer‘s reagent and Bromine water.

Arrange the following in order of decreasing reactivity towards alkanes. HCl, HBr, HI, HF

Description : Arrange the following in order of decreasing reactivity towards alkanes. HCl, HBr, HI, HF

Last Answer : Ans. HI> HBr> HCl >HF

Name two reagents which can be used to distinguish between ethene and ethyne.

Description : Name two reagents which can be used to distinguish between ethene and ethyne.

Last Answer : Ans. Tollen‘s reagent

Out of ethylene and acetylene which is more acidic and why?

Description : Out of ethylene and acetylene which is more acidic and why?

Last Answer : Ans. Acetylene, due to greater electonegativity of the sp hybridised carbon.

Arrange the following in the increasing order of C-C bond length- C2H6 , C2H4, C2H2

Description : Arrange the following in the increasing order of C-C bond length- C2H6 , C2H4, C2H2

Last Answer : Ans. C2H2 < C2H4 < C2H6

What effect does branching of an alkane chain has on its boiling point?

Description : What effect does branching of an alkane chain has on its boiling point?

Last Answer : Ans. As branching increases, the surface area of the molecule decreases which results in a small area of contact. As a result, the Van der Waals force also decreases which can be overcome at ... lower temperature. Hence, the boiling point of an alkane chain decreases with an increase in branching.

What are the necessary conditions for any system to be aromatic?

Description : What are the necessary conditions for any system to be aromatic?

Last Answer : Ans. A compound is said to be aromatic if it satisfies the following three conditions: (i) It should have a planar structure. (ii) The π-electrons of the compound are completely delocalized in the ring. (iii)The total number ... to (4n + 2), where n = 0, 1, 2 etc. This is known as Huckel s rule.

Explain why Grignard reagents do not reacts with alkanes.

Description : Explain why Grignard reagents do not reacts with alkanes.

Last Answer : Ans. In alkanes , the C – H bond has very little polarity . The hydrogen cannot be abstracted by the Grignard reagent.

What are the main constituent of LPG?

Description : What are the main constituent of LPG?

Last Answer : Ans. Butane and isobutane . Both these isomers can be easily liquified and hence can be conveniently transported in iron cylinder.

Is it possible to isolate pure staggered ethane or pure eclipsed ethane at room temperature? Explain .

Description : Is it possible to isolate pure staggered ethane or pure eclipsed ethane at room temperature? Explain .

Last Answer : The energy differences between staggered and eclipsed forms of ethane is just 12.55 kj mol_1 which is easily met by collisions of the molecules at room temperature. Therefore, it is not possible to isolate either pure staggered or pure eclipsed ethane at room temperature.

Which of the following has highest boiling point and why?(L-II) (a) 2 methylpentane (b) 2,3 dimethyl butane (c) 2,2 dimythylbutane

Description : Which of the following has highest boiling point and why?(L-II) (a) 2 methylpentane (b) 2,3 dimethyl butane (c) 2,2 dimythylbutane

Last Answer : Ans. As the branching increases, surface area decreases. As a result, magnitude of Vander Waals forces of attraction decreases and hence the boiling point decreases. Thus, the overall order of decreasing boiling point is: 2 methylpentane (333k) > 2,3 dimethylbutane (331k) > 2,2 dimethylbutane(323k)

Why do the C-C bonds rather than C-H bonds break during cracking of alkanes?

Description : Why do the C-C bonds rather than C-H bonds break during cracking of alkanes?

Last Answer : Ans. Since the bond dissociation energy of C-C bonds (348kj /mol) is lower than bond dissociation energy of C-H bonds (414kj/mol), therefore, during cracking of alkanes, C-C bonds break more early than C-H bonds.

(a) What effect the branching of an alkane has on its melting point? (L-III) (b) Which of the following has highest boiling point?(L-III) (1) 2-methyl pentane. (2) 2, 3-diethyl butane. (3) 2, 2- dimethyl butane.

Description : (a) What effect the branching of an alkane has on its melting point? (L-III) (b) Which of the following has highest boiling point?(L-III) (1) 2-methyl pentane. (2) 2, 3-diethyl butane. (3) 2, 2- dimethyl butane.

Last Answer : Ans.(a) In general conception, as the branching increases packing of the molecules in the crystals becomes less close and have melting point decreases accordingly. (b) As the branching increases, ... attraction decreases and hence the boiling point decreases. So, 2-methyl pentane has highest B.pt.

Arrange the three isomers of pentane in increasing order of their boiling points?

Description : Arrange the three isomers of pentane in increasing order of their boiling points?

Last Answer : Ans.2, 2-Dimethylpropane

Why are alkanes called paraffins?

Description : Why are alkanes called paraffins?

Last Answer : Paraffin’s means little affinity; alkanes due to strong C-C and C-H bonds are relatively chemically inert.

What are conformations?

Description : What are conformations?

Last Answer : Conformations are spatial arrangements which are obtained by rotation around sigma bonds.

Wich of the following is a method/process of disposing of solid waste which cannot be re-used or recycled? (1) Landfills (2) Incineration (3) Pyrolysis and Gasification (4) An the above

Description : Wich of the following is a method/process of disposing of solid waste which cannot be re-used or recycled? (1) Landfills (2) Incineration (3) Pyrolysis and Gasification (4) An the above

Last Answer : (4) An the above Explanation: Landfills, Incineration, Pyrolysis and Gasification are methods of disposing of solid waste which cannot be reused or recycled.

Which of the following is a method/process of disposing of solid waste which cannot be reused or recycled ? (1) Landfills (2) Incineration (3) Pyrolysis and Gasification (4) All the above

Description : Which of the following is a method/process of disposing of solid waste which cannot be reused or recycled ? (1) Landfills (2) Incineration (3) Pyrolysis and Gasification (4) All the above

Last Answer : All the above

Which is correct matched ? 1. Arsenic poisoning -Black foot disease. 2. Secondary Effluent treatment-Biological process. 3. Pyrolysis -Solid soil wast

Description : Which is correct matched ? 1. Arsenic poisoning -Black foot disease. 2. Secondary Effluent treatment-Biological process. 3. Pyrolysis -Solid soil wast

Last Answer : Which is correct matched ? 1. Arsenic poisoning -Black foot disease. 2. Secondary Effluent treatment-Biological process. 3. ... C. 2,3,4,5 D. 1,2,3,4

Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid and gas can be used to produce energy. (2) The process occurs at a temperature above 430°C at atmospheric pressure. (3) The process occurs under high pressure at temperature above 430° C. (4) It is a thermo chemical decomposition of organic waste

Description : Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid ... pressure at temperature above 430° C. (4) It is a thermo chemical decomposition of organic waste

Last Answer : (2) The process occurs at a temperature above 430°C at atmospheric pressure. Explanation: Pyrolysis is a thermo-chemical decomposition of organic material at elevated temperatures in the ... . Pyrolysis generally takes place well above atmospheric pressure at temperatures exceeding above 430 °C.

The biological decomposition of organic substances in wastes under controlled conditions known as - (1) composting (2) incineration (3) sanitary landfill (4) pyrolysis

Description : The biological decomposition of organic substances in wastes under controlled conditions known as - (1) composting (2) incineration (3) sanitary landfill (4) pyrolysis

Last Answer : (1) composting

Thermal pyrolysis of ethylene dichloride produces (A) Trichloroethylene (B) Vinyl chloride (C) Ethanol amine (D) Ethylene oxid

Description : Thermal pyrolysis of ethylene dichloride produces (A) Trichloroethylene (B) Vinyl chloride (C) Ethanol amine (D) Ethylene oxid

Last Answer : (B) Vinyl chloride

Which one of the following processes aims at producing higher yield of gaseous unsaturated hydrocarbons and aromatics like benzene & toluene? (A) Reforming (B) Pyrolysis (C) Alkylation (D) Hydrocracking

Description : Which one of the following processes aims at producing higher yield of gaseous unsaturated hydrocarbons and aromatics like benzene & toluene? (A) Reforming (B) Pyrolysis (C) Alkylation (D) Hydrocracking

Last Answer : (A) Reforming

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

Pyrolysis of kerosene or natural gasoline is done to produce mainly the (A) Olefins and aromatics (B) Lighter paraffins (C) Stabilised gasoline (D) Diesel

Description : Pyrolysis of kerosene or natural gasoline is done to produce mainly the (A) Olefins and aromatics (B) Lighter paraffins (C) Stabilised gasoline (D) Diesel

Last Answer : (A) Olefins and aromatic

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

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

Name the products obtained by combustion pyrolysis.

Description : Name the products obtained by combustion pyrolysis.

Last Answer : Fuel gas, ethanol and charcoal

What is combustion pyrolysis?

Description : What is combustion pyrolysis?

Last Answer : Combustion pyrolysis is a process of chemical decomposition at high temperature (upto o 500 C) in total or partial absence of air.

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

Radioactive solid nuclear wastes are disposed off by (A) High temperature incineration (B) Pathological incineration (C) Pyrolysis(D) Underground burial in concrete containers

Description : Radioactive solid nuclear wastes are disposed off by (A) High temperature incineration (B) Pathological incineration (C) Pyrolysis (D) Underground burial in concrete containers

Last Answer : (D) Underground burial in concrete containers

Vinyl chloride (CH2 = CH.Cl) is produced by the thermal pyrolysis of ethylene dichloride at a pressure & temperature of (A) 4 kgf/cm2 & 500°C (B) 10 kgf/cm2 & 1000°C (C) 40 kg/cm2 & 200°C (D) 100 kgf/cm2 & 500°C

Description : Vinyl chloride (CH2 = CH.Cl) is produced by the thermal pyrolysis of ethylene dichloride at a pressure & temperature of (A) 4 kgf/cm2 & 500°C (B) 10 kgf/cm2 & 1000°C (C) 40 kg/cm2 & 200°C (D) 100 kgf/cm2 & 500°C

Last Answer : (A) 4 kgf/cm2 & 500°C

Thermal pyrolysis of ethylene dichloride produces (A) Trichloroethylene (B) Vinyl chloride (C) Ethanol amine (D) Ethylene oxide

Description : Thermal pyrolysis of ethylene dichloride produces (A) Trichloroethylene (B) Vinyl chloride (C) Ethanol amine (D) Ethylene oxide

Last Answer : (B) Vinyl chloride

Temperature during hydrogenation of oil should not be more than 200°C, otherwise it will result in (A) Pyrolysis of oil(B) Sintering of porous catalyst(C) Hydrogen embrittlement(D) All (A), (B) and (C)

Description : Temperature during hydrogenation of oil should not be more than 200°C, otherwise it will result in (A) Pyrolysis of oil (B) Sintering of porous catalyst (C) Hydrogen embrittlement (D) All (A), (B) and (C)

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

Commercially ethylene is produced from naphtha by (A) Catalytic cracking (B) Catalytic dehydrogenation (C) Pyrolysis (D) Hydrocracking

Description : Commercially ethylene is produced from naphtha by (A) Catalytic cracking (B) Catalytic dehydrogenation (C) Pyrolysis (D) Hydrocracking

Last Answer : (D) Hydrocracking

Describe the following unit processes: (i) Pyrolysis (ii) Hydration (iii) Hydrogenation.

Description : Describe the following unit processes: (i) Pyrolysis (ii) Hydration (iii) Hydrogenation.

Last Answer : i)Pyrolysis: The decomposition of a compound by heat is called pyrolysis. Large alkane molecules are broken down to give lower molecular weight alkanes, alkenes and hydrogen. Eg: When ethane is heated to 500 ... Chemical Reaction for hydrogenation: CH2= CH2 + H2 → CH3-CH3 C6H6 + 3H2→C6H12

Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid and gas can be used to produce energy. (2) The process occurs at a temperature above 430°C at atmospheric pressure. (3) The process occurs under high pressure at temperature above 430° C. (4) It is a thermochemical decomposition of organic waste

Description : Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant ... high pressure at temperature above 430° C. (4) It is a thermochemical decomposition of organic waste

Last Answer : The process occurs at a temperature above 430°C at atmospheric pressure.

The biological decomposition of organic substances in wastes under controlled conditions known as (1) composting (2) incineration (3) sanitary landfill (4) pyrolysis

Description : The biological decomposition of organic substances in wastes under controlled conditions known as (1) composting (2) incineration (3) sanitary landfill (4) pyrolysis

Last Answer : composting