94420 + Interview Questions in Chemistry in Class 12

1.	Synthetic rubbers are usually obtained by copolymeisation of
Answer» ALKANE and 1, 3 - butandience 1,4 - polyisoprene urea and formaldehyde alkene and 1,3 -butadiene. Answer :D

Discussion

2.	Synthetic rubber is a polymer which resrmble natural rubber is:
Answer» Neoprene Chloroprene Glyptal Nylone Answer :A

Discussion

3.	Synthetic rubber is a copolymer of which ?
Answer» Buta-1,3-diene Buta-1,2-diene cis-1,4-isoprene NONE of these SOLUTION :Buta-1,3-diene

Discussion

4.	Synthetic rubber is:
Answer» Polyester Polyamide Polysaccharide Poly (halodiene) ANSWER :D

Discussion

5.	Synthetic rubber is :
Answer» POLYAMIDE POLYSACCHARIDE cellulose Polyhalodiene Answer :D

Discussion

6.	Synthetic rubber Buna-N is a polymer of
Answer» `H_(2)C = CH - CH = CH_(2) " and " C_(6)H_(5)- CH =CH_(2)` `H_(2)C= CH – CH " and " H_(2)C = CH - CH = CH_(2)` `H_(2)C=CH-CN and H_(2)C=CH-C=CH=CH_(2)overset(\|)CH_(3)` `H_(2)C=CH-C=CH_(2) and H_(2)C=CH CH=CH_(2)overset(\|)CL` Solution :`H_(2)C= CH – CH " and " H_(2)C = CH - CH = CH_(2)`

Discussion

7.	Synthetic polymers like polystyrene, silicones and PVC, are ............
Answer» SOLUTION :COLLOIDS

Discussion

8.	Synthetic polymers do not degrade in the environment for a long time. How can biodegradable synthetic polymers be made. Differentiate between biopolymers and biodegradable polymers and give examples of each type.
Answer» Solution :SYNTHETIC polymers are quite resistant to ENVIRONMENTAL degradation process and are responsible for the accumulation of polymeric solid WASTE materials. New biodegradable synthetic polymers have been designed and developed. These polymers contain similar functional group as present in biopolymers. e.g., : aliphatic polyesters Biopolymers can or can.t be biodogradable e.g. : Protein, starch etc., biodegradable but Keratin are non-biodegradabele. Biodegradable POLYMER are polymers which can be degradable always. e.g. : PHBV

Discussion

9.	Synthetic polymer prepared by using caprolactam is known as
Answer» terylene teflon nylon 6 NEOPRENE SOLUTION :

Discussion

10.	Synthetic human hair wigs are made from a Co-polymer of vinyl chloride and acrylonitrile and is called:
Answer» PVC Polyacrylonitrile Cellulose Dynel Answer :D

Discussion

11.	Synthetic fibres like nylon -66 are very strong because
Answer» They have high MOLECULAR weight and high melting points They have a high degree of cross linking by strong C-C bond They have LINEAR molecules consisting of very LONG chains They have linear molecules interlinked with forces LIKE HYDROGEN bonding . Answer :D

Discussion

12.	Synthetic human hair wigs are made from a copolymer of vinyl chloride and acrylonitrile and is called :
Answer» PVC Polyacrylonitrile PTFE Dynel ANSWER :D

Discussion

13.	Synthetic detergents are more effective in hard water than soaps because
Answer» they are non-ionic their `Ca^(++ )`and `Mg^(++)`salts are insoluble in water their `Ca^(++)` and `Mg^(++)` salts are water soluble they are highly soluble in water Solution :Structural features of soaps and DETERGENTS are almost same except that the POLAR end in detergents is `-OSO_3^(-)NA^+`while in soaps polar end is `-COO^(-)Na^+` Detergents have an advantage over soaps that its polar end sulphate and sulphonate retain their efficiency in HARD water, since the corresponding Ca and Mg salts are soluble. Being salts of STRONG acids, they yield neutral solution, in contrast, to the soaps, which being snits of weak acids yield slightly alkaline solutions.

Discussion

14.	Synthetic compounds which imprint a sweet sensation and possess no or negligible nutritional value are called ...............
Answer» SOLUTION :ARTIFICIAL sweatness

Discussion

15.	Synthetic biopolymer , PHBV is made up to the followingmonomers ,
Answer» 3-hydroxybutanoic acid +3-hydroxypentanoic acid 2-hydroxybutaoic acid +2-hydoxypropanoic acid 3-chlorobutanoic acid +3-chloropentanoicacid 2-chlorobutanoic acid +3-methylpentanoic acid. Solution :`underset("3-Hydroxybutanoic acid")(nCH_(3)-overset(OH)overset(\|)(CH)-CH_(2)COOH)+underset("3-Hydroxypentanoic acid")(nCH_(3)CH_(2)-overset(OH)overset(\|)(CH)-CH_(2)COOH) tounderset(PHBV)([--O-underset(CH_(3))underset(\|)(CH)-CH_(2)-underset(O)underset(\|\|)C-underset(CH_(2)CH_(3))underset(\|)(CH)-CH_(2)-underset(O)underset(\|\|)(C)--]_(n)`

Discussion

16.	Synthesise the following compounds : a. b.Benzene rarr 2,4-D (2,4-Dichlorophenoxy acetic acid, broad leaf week killer) c.Nitrobenzene rarr PAS (p-Amini salicylic acid, Aniti-tuberculosis drug) d. e.Chlorobenzene rarr f.Phenol rarr overset (Methyl salicylate) underset (Oil of wintergreen, a flavouring agent) g. h.Benezene rarr
Answer» SOLUTION :a. B. c. d. e. f. g. H.

Discussion

17.	Synthesise the following : a.Butene to butanol and butan-2-ol 1-Chloro propane to pentanol and pentan-2-ol c.Benzene to 3-(4-chorophyl propan-1-ol) e. Ethyne to butanol Propane to allyl alcohol f. Propane to allyl acohol g. Propane to propanol and propan-2-ol
Answer» Solution :a. Hydrobration oxidation PROCEEDS with anti-Markovnikov addition, so it WOULD give (I), while acide-cataylsed hydration and mercuration-demercuration reaction proceed with Merkovnikov addition, so it would give (II). Synthesis: i. ii. b. The 4C-atom chain has to be increased to 5C-chain by a GR. with `CH_(2)=O`. (I) c. The 3C-atom chain has to be increased to 5C-chain by a E. F.`overset (MeCH_(2)Me) underset (Propane (A))``rarr H_(2)C` == `overset (CH--CH_(2) OH) underset (Allyl aclohol (I))`

Discussion

18.	Synthesis of propellane takes placed by the following route. Q. The product (w) is:
Answer» SOLUTION :(A). `2Cu^(2+)+2H_(2)Oto2Cu+O_(2)+4H^(+)` (B) `CU(a)+Cu^(2+)TOCU^(2+)+Cu(c)` (c). `MgCl_(2)+2H_(2)OtoMg(OH)_(2)+H_(2)+Cl_(2)` partically `O_(2)` will (d). `MgCl_(2)toMg+Cl_(2)`

Discussion

19.	Synthesis of identical copies of DNA is called
Answer» TRANSCRIPTION REPLICATION TRANSLATION REVERSE transcription Answer :B

Discussion

20.	Synthesis of ester involves the reaction of alcohol with
Answer» a KETONE an amide `CH_(3)MGBR` `RCOOH` Answer :D

Discussion

21.	Synthesis of each molecule of glucose in photosynthesis involves :
Answer» 18 molecules of ATP 10 molecules of ATP 8 molecules of ATP 6 molecules of ATP SOLUTION :18 molecules of ATP

Discussion

22.	Synthesis ofcyclohexane-1,2diolfromcyclohexenemay beaccomplished in twoways : I . MnO_(4) dilute OH, O^(@)C dihydroxylation II . Peracid epoxidationfollowedby NaOH openingof theepoxidering . Whichof thefollowingstatementabout theproductsfromthesereactionsis correct?
Answer» MethodsI and IIgivesameproduct METHOD Igivesresolvableracemicmixturewhilemethod IIwill GIVE non-resolvableachiralproduct Method I givesresolvable opticallyinactivecompoundwhilemethod IIgivesresolvableracemicmixture ProductsobtainedthroughmethodI and IIwillhavediasteriomericrelationship Solution :NA

Discussion

23.	Synthesies the following ethers, selec-ting the given methods. (I) Williamson's synthesis (II) Alkoxy mercuration-demercuration (III) Intermolecular dehydration Given reasons for the selection of the method. a.Divinyl ether b.Dicyclohoexyl ether c.Propyl sec-butyl ether d.1-Propoxy-2-methyl propane e.1-(3-Mrthyl butoxy)-3-methyl butane
Answer» Solution :a.Write the structures of ether: since it is an unstable compopund and tautomerise to `H_(3)C--CH=O`. Double BOND is introduced after the formation of ether by method (III). Method (I) cannot be used because of unreactive vinyl halideand vinyl oxideboth are stabilised by reasonance.Method (II) cannot be used because of unreactive vinyl alcohol. b.Structure of ether : Method (II) will give desired result with Although it is symmetrical ether, but method (III) cannot be used because intromlecular dehydration of `2^(@)` ROH would give mainly cyclohexene.Method (I) cannot be used because `2^(@)` RX does not favour the reaction. c.Structure of ether. By method (II): i. ii. Path (ii) is not feasible because it would give different ether (isopropyl-sec-butyl ether) (F). Path (i) would give the required ether: d.Structure of the ether: Method I is feasible: Methods II and III are not feasible and method II would give different isomers. Path (i): Path (ii): Method III is not feasible. It is a non-symmetrical ether, dehydration gives mixtures and both alkyl groups are `1^(@)` . `R--O--H + R'O---H OVERSET (Conc.H_(2)SO_(4)) underset (Low TEMP) rarr` `R--O--R' + R--O--R + R'--O--R` e.Structure of ether: Method III is feasible. It is a symmetrical ether and with `1^(@) (R---)` groups. Method I is not feasible. Both RX and R'ONa wold be `1^(@)`. Better yield of ether is OBTAINED FORM `1^(@)` RX and `3^(@)` RONa.Method II is not feasible, it would give a different ether.

Discussion

24.	Synthesis gas is a mixture of :
Answer» STEAM and CARBON MONOXIDE Carbon monoxide and nitrogen Hydrogen and carbon monoxide Hydrogen and methane Answer :C

Discussion

25.	Synthesies the following alcohols by using: a.Grignard reagent (G.R.) b.Not using G.R. (any other method). (I) (II) (III) (IV) (V)
Answer» SOLUTION :a. SYNTHESIS by using G.R. (I) (II) (III) (IV) (V) (B) Synthesis of ALCOHOLS without using G.R. (I) (II) (III) (IV)

Discussion

26.	Symmetrically subsituted epoxides give the same products in both the acid catalysed and base catalyzed ring opening. An unsymmetrical epoxide gives different products under acid catalysed and base catalysed conditions. Under basic contions, the alkoxide ion simply attacks the less hindered carbon atom in an SN^(2) displacement. Under acidic conditions, the alcohol, attacks the protonated epoxide. Structure II and III show that the oxtrane carbon share part of positive charge. The tertiary carbon bear a larger part of positive charge and it is more strongly electrophilic. The bond between teritiary carbon and oxygen is weaker implying a lower transition state energy for attack at the teritary carbon. Attack by the weak nucleophilic is sensitive to the strength of electrophilic is sensitive to the strength of electrophile. Center attack takes place at more electrophilic carbon which is usually the more substituted carbon because it can better support the positive charge.
Answer» SOLUTION :N//A

Discussion

27.	Symmetrically subsituted epoxides give the same products in both the acid catalysed and base catalyzed ring opening. An unsymmetrical epoxide gives different products under acid catalysed and base catalysed conditions. Under basic contions, the alkoxide ion simply attacks the less hindered carbon atom in an SN^(2) displacement. Under acidic conditions, the alcohol, attacks the protonated epoxide. Structure II and III show that the oxtrane carbon share part of positive charge. The tertiary carbon bear a larger part of positive charge and it is more strongly electrophilic. The bond between teritiary carbon and oxygen is weaker implying a lower transition state energy for attack at the teritary carbon. Attack by the weak nucleophilic is sensitive to the strength of electrophilic is sensitive to the strength of electrophile. Center attack takes place at more electrophilic carbon which is usually the more substituted carbon because it can better support the positive charge.
Answer» NONE of these Solution :N//A

Discussion

28.	Symmetrically subsituted epoxides give the same products in both the acid catalysed and base catalyzed ring opening. An unsymmetrical epoxide gives different products under acid catalysed and base catalysed conditions. Under basic contions, the alkoxide ion simply attacks the less hindered carbon atom in an SN^(2) displacement. Under acidic conditions, the alcohol, attacks the protonated epoxide. Structure II and III show that the oxtrane carbon share part of positive charge. The tertiary carbon bear a larger part of positive charge and it is more strongly electrophilic. The bond between teritiary carbon and oxygen is weaker implying a lower transition state energy for attack at the teritary carbon. Attack by the weak nucleophilic is sensitive to the strength of electrophilic is sensitive to the strength of electrophile. Center attack takes place at more electrophilic carbon which is usually the more substituted carbon because it can better support the positive charge.
Answer» NONE SOLUTION :N//A

Discussion

29.	Syn gas is ……..
Answer» `CO+N_(2)` `CO+H_(2)` `CO_(2)+H_(2)` `CO_(2)+N_(2)` Answer :B

Discussion

30.	Symmetrical alkane is prepared from which of the following reaction ?
Answer» Resenmund's REACTION Carbylamine reaction Reimer-Tieman reaction WURTZ reaction Answer :D

Discussion

31.	Symmetrically subsituted epoxides give the same products in both the acid catalysed and base catalyzed ring opening. An unsymmetrical epoxide gives different products under acid catalysed and base catalysed conditions. Under basic contions, the alkoxide ion simply attacks the less hindered carbon atom in an SN^(2) displacement. Under acidic conditions, the alcohol, attacks the protonated epoxide. Structure II and III show that the oxtrane carbon share part of positive charge. The tertiary carbon bear a larger part of positive charge and it is more strongly electrophilic. The bond between teritiary carbon and oxygen is weaker implying a lower transition state energy for attack at the teritary carbon. Attack by the weak nucleophilic is sensitive to the strength of electrophilic is sensitive to the strength of electrophile. Center attack takes place at more electrophilic carbon which is usually the more substituted carbon because it can better support the positive charge. What will be the products in following reactions
Answer» SOLUTION :N//A

Discussion

32.	Symmetrical alkane can be prepared from alkyl halideby,
Answer» Wurtzs REACTION Cannizzaros reaction Hoffmanns reaction Mendius reaction Answer :A

Discussion

33.	Symbolic name for teflon is:
Answer» PTFE PCTFE PVC None of these Answer :A

Discussion

34.	Sym-Tribromobenznene is ………
Answer» ANSWER :B

Discussion

35.	Swimming pools are disinfected by bubbling through water in controlled quantity of:
Answer» `Br_2` `Cl_2` `O_2` ENRICHED AIR `N_2` ANSWER :B

Discussion

36.	Sweet spirit of nitre is used as ………………….
Answer» ANSWER :DIURETIC

Discussion

37.	Sweet spirit of nitre is
Answer» ETHYL NITRITE Nitrobenzene Chlorobenzene Nitroethane. Solution :Ethylnitrite is USED as siuretic.

Discussion

38.	Sweet fruity smell is obtained by the reaction of ethanol with ……..
Answer» `PCI_(3)` `CH_(3)-O-CH_(3)` `CH_(3)COOH` `SOCl_(2)` Solution :`C_(2)H_(5)OH+ CH_(3)COOH to CH_(3)COOC_(2)H_(5)+ H_(2)O` Esther is a compound having fruity smell.

Discussion

39.	Swati's father wanted to go to the hospital to see his ailing friend. Swati insisted to accompany his father. On reaching the hospital, swati noticed a perculiar smell. after reading the above passage, answer the following questions: (i) Name the chemical which causes the hospital smell. (ii) What is the use of this chemical and how does it work?
Answer» Solution :(i) the hospital smell is not that of a particular disease but is the smell of a chemical compound called iodoform `(CHI_(3))`. (ii) Iodoform is a mild disinfectant and is used for CLEANING the FLOORS of the corridors, WARDS, etc. it can also be used as an antiseptic for skin INFECTIONS, sores, bruises, BOILS, burns, etc. when applied on skin, iodoform decomposes to release iodine. it is iodine which acts as the actual antiseptic, killing bacteria and fungi. iodoform is also safer than other antiseptics if it is accidently swallowed.

Discussion

40.	Swart reaction is used to prepare
Answer» R-F R-Cl R-Br R-I Answer :A

Discussion

41.	Suspension of slaked lime in water is called :
Answer» WASHING of lime Quick lime Milk of lime None of these Answer :C

Discussion

42.	Suspended impurities from a colloidal solution of gum in water can be removed by
Answer» FILTRATION dialysis electrodialysis ultrafiltration SOLUTION :Suspended IMPURITIES can be REMOVED from a colloidalsolution by filtration through an ordinary filter paper. Colloidal solution can easily pass through an ordinary filter paper.

Discussion

43.	Surfactants and detergents have the same common property of_____ in them:
Answer» Detergency Surface activity Viscosity NONE ANSWER :B

Discussion

44.	Surfacetant molecules can cluster together as micelles, which are colloid sized cluster of molecules. Micellesfrom only above critical micelle concentration (CMC) and above centain temperature called K raft temperature. DeltaH of micelle formation can be positive or negative. Which is correct statement(s) about micelle formation?
Answer» `DeltaS` of MICELLE formation is positive the hydrophobic PART lie towards interior of micelle the hydrophilic part lie towards SURFACE of micelle `DeltaS` of micelle formation is negative Answer :BCD

Discussion

45.	Surface tension of lyophobic sols is usually
Answer» LOWER than DISPERSION medium More than dispersion medium Equal to dispersion medium Can't predict Answer :A

Discussion

46.	Surface tension of lyophilic sols is:
Answer» LOWER than that of `H_2O` More than that `H_2O` EQUAL to that of `H_2O` NONE of these Answer :A

Discussion

47.	Surface tension of lyophilic sol is
Answer» LOWER than that of `H_(2)O` More than that of `H_(2)O` EQUAL to that of `H_(2)O` NONE of these Solution :N//A

Discussion

48.	Surface layer of solid means
Answer» atoms PERESENT in the upper LAYER of the solid . atoms present upto a depth of 100 NM on the SURFACE . atoms present in the bulk of the solid . atoms of surface of solid not precocupied by other substances . Solution :Area up to a depth of 100 nm

Discussion

49.	Surface layer of a solid means
Answer» atoms PRESENT in the upperlayer of the solid atoms present upto a depth of 100 NM on the surface atoms present in the bulk of the solid atoms of the surface of a solid not PREOCCUPIED by other substances Answer :B

Discussion

50.	Supposingthe energy of the energy levelsin the hydrogen atom is given under Energy level K L M N.. n=1 n=2n=3 n=4=n=infty Total energy of anat n =1 is 864 a.u the ecitation energy needed to raise the electron from M levelto n= infty wouldbe :
Answer» 192 96 188 384 Answer :B

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Synthetic rubbers are usually obtained by copolymeisation of

Synthetic rubber is a polymer which resrmble natural rubber is:

Synthetic rubber is a copolymer of which ?

Synthetic rubber is:

Synthetic rubber is :

Synthetic rubber Buna-N is a polymer of

Synthetic polymers like polystyrene, silicones and PVC, are ............

Synthetic polymers do not degrade in the environment for a long time. How can biodegradable synthetic polymers be made. Differentiate between biopolymers and biodegradable polymers and give examples of each type.

Synthetic polymer prepared by using caprolactam is known as

Synthetic human hair wigs are made from a Co-polymer of vinyl chloride and acrylonitrile and is called:

Synthetic fibres like nylon -66 are very strong because

Synthetic human hair wigs are made from a copolymer of vinyl chloride and acrylonitrile and is called :

Synthetic detergents are more effective in hard water than soaps because

Synthetic compounds which imprint a sweet sensation and possess no or negligible nutritional value are called ...............

Synthetic biopolymer , PHBV is made up to the followingmonomers ,

Synthesise the following : a.Butene to butanol and butan-2-ol 1-Chloro propane to pentanol and pentan-2-ol c.Benzene to 3-(4-chorophyl propan-1-ol) e. Ethyne to butanol Propane to allyl alcohol f. Propane to allyl acohol g. Propane to propanol and propan-2-ol

Synthesis of propellane takes placed by the following route. Q. The product (w) is:

Synthesis of identical copies of DNA is called

Synthesis of ester involves the reaction of alcohol with

Synthesis of each molecule of glucose in photosynthesis involves :

Synthesis ofcyclohexane-1,2diolfromcyclohexenemay beaccomplished in twoways : I . MnO_(4) dilute OH, O^(@)C dihydroxylation II . Peracid epoxidationfollowedby NaOH openingof theepoxidering . Whichof thefollowingstatementabout theproductsfromthesereactionsis correct?

Synthesis gas is a mixture of :

Synthesies the following alcohols by using: a.Grignard reagent (G.R.) b.Not using G.R. (any other method). (I) (II) (III) (IV) (V)

Syn gas is ……..

Symmetrical alkane is prepared from which of the following reaction ?

Symmetrical alkane can be prepared from alkyl halideby,

Symbolic name for teflon is:

Sym-Tribromobenznene is ………

Swimming pools are disinfected by bubbling through water in controlled quantity of:

Sweet spirit of nitre is used as ………………….

Sweet spirit of nitre is

Sweet fruity smell is obtained by the reaction of ethanol with ……..

Swart reaction is used to prepare

Suspension of slaked lime in water is called :

Suspended impurities from a colloidal solution of gum in water can be removed by

Surfactants and detergents have the same common property of_____ in them:

Surface tension of lyophobic sols is usually

Surface tension of lyophilic sols is:

Surface tension of lyophilic sol is

Surface layer of solid means

Surface layer of a solid means

Supposingthe energy of the energy levelsin the hydrogen atom is given under Energy level K L M N.. n=1 n=2n=3 n=4=n=infty Total energy of anat n =1 is 864 a.u the ecitation energy needed to raise the electron from M levelto n= infty wouldbe :