94420 + Interview Questions in Chemistry in Class 12

1.	Isoprene is synthetic rubber.True or false ?
Answer» SOLUTION :Buna-S is a SYNTHETIC RUBBER.

Discussion

2.	Keto-enol tautomerism is observed in :
Answer» `C_(6)H_(5)overset(O)overset(\|\|)(C)-H` `C_(6)H_(5)UNDERSET(O)underset(\|\|)(C)-CH_(3)` `C_(6)H_(5)-overset(O)overset(\|\|)(C)-C_(6)H_(5)` `C_(6)H_(5)-overset(O)overset(\|\|)(C)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(C)-C_(6)H_(5)` Answer :B

Discussion

3.	Keto-enol tautomerism is not observed in:
Answer» `C_(6)H_(5)COC_(6)H_(5)` `C_(6)H_(5)COCH=CH_(2)` `C_(6)H_(5)COCH_(2)COCH_(3)` `CH_(3)COCH_(2)COCH_(3)` Answer :A

Discussion

4.	Isoprene is a valuable subtance for making
Answer» Propene Liquid FUEL Synthetic rubber Petrol SOLUTION :Rubber is a polymer of ISOPRENE, its chamical formula is `(C_(2)H_(8))_(n)`.

Discussion

5.	Isoprene is a valuable substance for making
Answer» propene liquid fuel synthetic RUBBER petrol SOLUTION :Rubber is a POLYMER of ISOPRENE.

Discussion

6.	Kerosene is used as fuel because it is
Answer» LESS volatile More volatile Cheap Abundantly available Answer :A

Discussion

7.	Write the structure of isoprene (2-methyl -1,3-butadiene).
Answer» STARCH SYNTHETIC RUBBER NATURAL rubber PVC Answer :C

Discussion

8.	Isopentane on monochlorination gives....isomers and out of them ....... Are optically active.
Answer» `3,1` `4,2` `3,2` `4,1` SOLUTION :

Discussion

9.	Keratin presen t in hair is,
Answer» FIBROUS protein Globular protein Denatured protein Lipo protein Answer :A

Discussion

10.	Isopentane, (CH_(3))_(2)CHCH_(2)CH_(3) can form four isomeric monochloro derivatives. How many of these are optically active?
Answer» 1 2 3 4 Answer :B

Discussion

11.	Kerosencesi a mixtureof :
Answer» Aromatichydorcarbons alphatichydrocarbons saturatedhydrocarbons Alicylichydrocarbons ANSWER :B

Discussion

12.	Isonitriles on reduction give
Answer» `1^(@)` amine `3^(@)` amine `2^(@)` amine Quarternary ammonium salts Answer :C

Discussion

13.	Keratin, a structural protein is present in:
Answer» Hair Skin Wool Horn Answer :C

Discussion

14.	Keratin, glucosemannose, starch , cellulose .
Answer» SOLUTION :Kertain, COLLAGEN , GLYCINE, ALANINE, INULIN , insulin.

Discussion

15.	Keratin is a _____ type protein.
Answer» ANSWER :FIBROUS

Discussion

16.	Keen observation of the rates of reaction about the series of steps leading to the formation of products is called the reaction mechanism . The reaction between H_(2) and I_(2) to form hydrogen iodide was originally postulated as a simple one step reaction H_(2) + I_(2) to 2 HI Rate = k [H_(2)][I_(2)] but the formation of HI has been explained on the basis of the following mechanism ({:( I_(2) , to , 2 I "(fast)" , ... (i) ), ( H_(2) + I , to , H_(2) I "(fast)" , ... (ii)) , (H_(2) I + I , to , 2HI "(slow)" , ... (iii) ):})/("overall" H_(2) + I_(2) to 2 HI For the reaction 2NO_(2) + F_(2) to 2 NO_(2) F following mechanism has been provided NO_(2) + F_(2) overset("slow")(to) NO_(2)F + F NO_(2) + F overset("fast")(to) NO_(2)F Thus rate expression of the above reaction can be written as
Answer» `r = k[NO_(2)]^(2) [F_(2)]` `r = k[NO_(2)]` `r = k [NO_(2)][F_(2)]` `r = k [F_(2)]` Solution :Rate is GIVEN by the SLOWEST step of the REACTION so rate is r = `k[NO_(2)][F_(2)]`.

Discussion

17.	Keen observation of the rates of reaction about the series of steps leading to the formation of products is called the reaction mechanism . The reaction between H_(2) and I_(2) to form hydrogen iodide was originally postulated as a simple one step reaction H_(2) + I_(2) to 2 HI Rate = k [H_(2)][I_(2)] but the formation of HI has been explained on the basis of the following mechanism ({:( I_(2) , to , 2 I "(fast)" , ... (i) ), ( H_(2) + I , to , H_(2) I "(fast)" , ... (ii)) , (H_(2) I + I , to , 2HI "(slow)" , ... (iii) ):})/("overall" H_(2) + I_(2) to 2 HI For the reaction 2NO(g) + 2H_(2)(g)to N_(2)(g) + 2H_(2)O(g) the rate expressions can be written in the following ways (d[N_(2)])/(dt) = k_(1) [NO] [H_(2)] , (d[H_(2)O])/(dt) = k [NO] [H_(2)] - (d[NO])/(dt) = k'_(1) = [NO] [H_(2)] , - (d[H_(2)])/(dt)= k''_(1) [NO][H_(2)] The relationship between k , k_(1) , k'_(1) , k''_(1)is
Answer» ` k = k_(1) = k'_(1) = k''_(1)` `k = 2k_(1) = k'_(1) = k''_(1)` `k = 2k'_(1) = k_(1) = k''_(1)` `k = k_(1) = k'_(1) = 2k''_(1)` SOLUTION :`-(1)/(2) (d[NO])/(DT) = -(1)/(2) (d[H_(2)])/(dt) = (d[N_(2)])/(dt) = (1)/(2) (d[H_(2)O])/(dt)` `(1)/(2) k'_(1) [NO] [H_(2)] = (1)/(2) k''_(1) [NO][H_(2)] = k_(1) [NO][H_(2)]` = `(1)/(2) k[NO][H_(2)] therefore k'_(1) = k''_(1) = 2k_(1) = k`

Discussion

18.	Isomorphism.
Answer» SOLUTION :A phenomenon in which TWO or more crystalline substances show same scrystalline structure is CALLED isomophism and the crystals are said to be isomorphous. For example, `K_(2)SO_(4)` and `K_(2)SeO_(4)`.

Discussion

19.	Kerain, collagen, glycine, alanine, inulin, insulin.
Answer» SOLUTION :INULIN. It is a carbohydrates WHEREAS others are proteins.

Discussion

20.	K_(e ) for the reaction N_(2)(g)+O_(2) hArr 2NO(g) at 300 K is 4.0xx10^(-6). K_(p) for the above reaction will be (R=2 " cal mol"^(-1)K^(-1))
Answer» `2.4xx10^(-3)` `4xx10^(-6)` `4xx10^(-6) (RT)^(2)` `16xx10^(-12)` Solution :`K_(p)=K_(E )(RT)^(Delta N) " since " Delta n=0, K_(p)=K_(e )`

Discussion

21.	Isomers whose molecular structures are non-superimposable mirror images of each other are called :
Answer» DIASTEREOMERS mesomers enantiomers metamers Answer :C

Discussion

22.	KE of one mole of He at 0°C is
Answer» 84.43 cal 8.143 cal 819.0 cal none of these Answer :C

Discussion

23.	Isomers which can be interconverted through rotation around a single bond are
Answer» Conformers Diastereomers Enantiomers Positional ISOMERS Solution :Isomers obtained by the rotation of C-C SINGLE bond are CALLED conformers.

Discussion

24.	The kinetic energy of any gas molecule at 0^@C is :
Answer» 819.0 cal 84.43 cal 8.143 cal None Answer :A

Discussion

25.	Isomers which can be interconverted through rotation around a single bond are:
Answer» POSITION isomerws enantiomers metameres conformers Answer :D

Discussion

26.	K_(e ) " for " PCl_(5)(g) hArr PCl_(3) (g)+Cl_(2)(g) is 0.04 at 250^(@)C. How many moles of PCl_(5) must be added to a 3L flask to obtain a Cl_(2) concentration of 0.15 M
Answer» 4.2 MOLES 2.1 moles 5.5 moles 6.3 moles Solution :At EQUILIBRIUM the moles of `Cl_(2)` MUST be =`0.15xx3=0.45` `PCl_(5) HARR PCl_(3)+Cl_(2)` `(x-0.45)/(3) "" (0.45)/(3) (0.45)/(3)` Eqb. CONC. `K_(e )=([PCl_(3)][Cl_(2)])/([PCl_(5)])` `therefore 0.04=(0.15xx0.15)/((x-0.45)//3) "" therefore x=2.1` moles

Discussion

27.	Isomers which can be inter converted through rotation around a single bond are
Answer» POSITION of ISOMERS DIASTEROMERS ENANTIOMERS Conformers Answer :B

Discussion

28.	KCN reacts readily to give a cyanide with
Answer» Ethyl alcohol Ethyl BROMIDE Bromobenzene Chlorobenzene SOLUTION :`C_(2)H_(5)Br+KCNoverset("alcohol")rarrC_(2)H_(5)CN+KBr`.

Discussion

29.	Isomers of propionic acid are
Answer» `HCOOC_(2)H_(5)` and `CH_(3)COOCH_(3)` `HCOOC_(2)H_(5)` and `C_(3)H_(7)COOCH_(3)` `CH_(3)COOCH_(3)` and `C_(3)H_(7)OH` `C_(3)H_(7)OH` and `CH_(3)COCH_(3)` Answer :A

Discussion

30.	KCN reacts to form cyanide with :
Answer» Ethanol Bromoethane Bromobenzene Chlorobenzene Answer :B

Discussion

31.	KCN is used for the separation of :
Answer» `NA^(+) and K^(+) ` `Cu^(2+) and CD^(2+) ` `Ba^(2+) and Ca^(2+)` `ZN^(2+) and Cd^(2+) ` Answer :B

Discussion

32.	Isomers in coordination chemistry include many types. In structural isomers hydrate or solvent isomers, ionisation isomers and coordination isomers have same overall formula but have different ligands attached to the central atom or ion. The term linkage isomerism or ambidentate isomerism are used for cases of bonding through different through different atoms of the same ligand. Stereoisomers have the same ligands, but differ in the geometric arrangement of the ligands. Ma_(3).b_(3) complex has two geometrical forms(I) Facial (II) Meridonial then which of the following statement is incorrect ?
Answer» In facial isomer THREE same ligands occupy ADJACENT positions on OCTAHEDRON FACE In meridional isomers same ligands are present at `90^(@)" and "180^(@)` angles In facial isomer same ligands are present only at `90^(@)` angle Both isomers (facial and meridonial) are OPTICALLY active Answer :D

Discussion

33.	KCN is used for separting
Answer» `CO^(2+)` and `Ni^(2+)` `Mn^(2+)` and `ZN^(2+)` `BA^(2+)` and `Ca^(2+)` `Cu^(2+)` and `Cd^(2+)` SOLUTION :KCN is used for regerating `CO^(+2)` and `Na^(2+), Cu^(2+)` and `Cd^(2+)`

Discussion

34.	Isomers in coordination chemistry include many types. In structural isomers hydrate or solvent isomers, ionisation isomers and coordination isomers have same overall formula but have different ligands attached to the central atom or ion. The term linkage isomerism or ambidentate isomerism are used for cases of bonding through different through different atoms of the same ligand. Stereoisomers have the same ligands, but differ in the geometric arrangement of the ligands. Which of the following is not correctly matched against indicated isomerism ?
Answer» `[Co(NH_(3))_(4)(H_(2)O)Cl]Br,:"Ionisation isomerism"` `[Rh(PPh_(3))_(2)(CO)(NCS)_(2)] :"Linkage isomerism"` `[PT(NH_(3))_(4)][(PtCl_(4))] :"COORDINATION isomerism"` `[Zn(gly)_(2)]"tetrahedral":"Geometrical isomerism"` ANSWER :D

Discussion

35.	KCN is used for separating:
Answer» `Co^(2+)` and `NI^(2+)` `Mn^(2+)` and `Zn^(2+)` `Ba^(2+)` and `CA^(2+)` None Answer :A

Discussion

36.	KCN is used for separating
Answer» `CO^(+2)` and `Ni^(+2)` `MN^(+2)` and `ZN^(+2)` `Ba^(+2)` and `Ca^(+2)` `Cu^(+2)` and `Cd^(+2)` Solution :a) `Cd^(2+) overset(KCN+H_(2)S)to underset("YELLOW ppt")(CDS darr)""`b) `Cu^(2+) overset(KCN)to K_(3) underset("soluble complex")([Cu[CN]_(4)])` c) `Co^(2+)+2CN^(-) to Co^(2+) underset("Reddul brown ppt")([CN]_(2)darr)""`d)` Ni^(+2)+2CN^(-) to underset("green ppt")(Ni(CN)_(2)darr)`

Discussion

37.	Isomers have essentially identical :
Answer» STRUCTURAL formula Chemical properties Molecular formula Physical properties Answer :C

Discussion

38.	KCN is highly poisonous while K_(4)[Fe(CN)_(6)] is not. Why ?
Answer» Solution :KCN ionizes to give `CN^(-)` ions which combine with the protein (cytochrome 'c') present in the BLOOD and thereby block the oxygen binding site of the ENZYME resulting into DEATH `KCNrarrK^(+)+CN^(-)` `K_(4)[Fe(CN)_(6)]` ionizes as `K_(4)[Fe(CN)_(6)]rarr4 K^(+)+[Fe(CN)_(6)]^(4-)` The complex ion `[Fe(CN)_(6)]^(4-)` does not ionize to give `CN^(-)`ions. Hence, it is not toxic.

Discussion

39.	KClO_(3) to KCl + O_(2)(unbalanced), If in above reaction 5 moles of KClO_(3) was heated, then find moles of O_(2) produced on completion of reaction.
Answer» ANSWER : `(##ALN_NC_CHM_MC_E01_020_A01##)` `7.5`

Discussion

40.	Isomers have essentially identical.
Answer» STRUCTURAL formula Chemical properties Molecular formula Physical properties Solution :N//A

Discussion

41.	Isomerism shown by CH_(3)-(CH_(2))_(3)-O-CH_(3) CH_(3)-CH_(2)-O-CH_(2)-CH_(2)-CH_(3) CH_(3)-underset(CH_(3))underset(\|)(CH)-O-CH_(2)-CH_(3) is
Answer» POSITION isomerism Chain isomerism Metamerism Optical isomerism Solution :Metamerism is shown by the different ARRANGEMENT of ALKYL GROUP about functional group.

Discussion

42.	KClO_3 on heating decomposes to give KCl and O_2 What is the volume of O_2 at N.T.P liberated by 0.1 mole of KClO_3 ?
Answer» ANSWER :3.36 L

Discussion

43.	Isomers are different compounds that have the same
Answer» empirical formula molecular formula precentage composition all of these Solution :ISOMERS contain the same numbers of the same kinds of atoms and hence have tha same molecular formula. Ethyne `(C_(2)H_(2))`and BENZENE `(C_(6)H_(6))` have the same percentage composition and same emirical formula but they are not isomers as they differe in molecular formula.

Discussion

44.	Isomerisom present in CrCl_(3)6H_(2)O is…………..
Answer» SOLVATE isomerism Ligand isomerism Linkage isomerism Ionisation isomerism Answer :A

Discussion

45.	KClO_(3) overset( "conc. HCl") ( rarr) X_("(g)") + Y_("(g)") X= ? Y= ?
Answer» `O_(2) + Cl_(2) + ClO_(2)` `Cl_(2) + ClO_(2)` `CO_(2) + Cl_(2) ` `O_(2) + ClO_(2)` Solution :`KClO_(3) + 2HCl rarr underset("[Y]")(ClO_(2))+underset("[X]")(Cl_(2)) + KCl + H_(2)O`

Discussion

46.	Isomerization of glucose products
Answer» galactose fructose mannose allose Answer :B

Discussion

47.	Isoomerisms exhibited by [Cr(NH_(3))_(2)(H_(2)O)_(2)Cl_(2)]^(+) are
Answer» Isonisation, OPTICAL Hydrate , optical Geometrical , optical COORDINATE , geometrical ANSWER :C

Discussion

48.	KCl, KNO_(3) etc. are preferred in a salt bridge because they have equal____.
Answer» SOLUTION :TRANSPORT NUMBER

Discussion

49.	Isomerism shown by 2,3-dichlorobutane is
Answer» DIASTEREOMERISM Optical isomerism geometric isomerism structural isomerisms Solution :`UNDERSET(1)(CH_3)-overset(Cl)overset(\|)underset(2)(CH)-overset(Cl)overset(\|)underset(3)(CH)-underset(4)(CH_3)` 2nd and 3rd carbons are Chiral.

Discussion

50.	KCl is added to Fe(OH)_3 sol?
Answer» Solution :`FE(OH)_3` GETS COAGULATED.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Isoprene is synthetic rubber.True or false ?

Keto-enol tautomerism is observed in :

Keto-enol tautomerism is not observed in:

Isoprene is a valuable subtance for making

Isoprene is a valuable substance for making

Kerosene is used as fuel because it is

Write the structure of isoprene (2-methyl -1,3-butadiene).

Isopentane on monochlorination gives....isomers and out of them ....... Are optically active.

Keratin presen t in hair is,

Isopentane, (CH_(3))_(2)CHCH_(2)CH_(3) can form four isomeric monochloro derivatives. How many of these are optically active?

Kerosencesi a mixtureof :

Isonitriles on reduction give

Keratin, a structural protein is present in:

Keratin, glucosemannose, starch , cellulose .

Keratin is a _____ type protein.

Isomorphism.

Kerain, collagen, glycine, alanine, inulin, insulin.

K_(e ) for the reaction N_(2)(g)+O_(2) hArr 2NO(g) at 300 K is 4.0xx10^(-6). K_(p) for the above reaction will be (R=2 " cal mol"^(-1)K^(-1))

Isomers whose molecular structures are non-superimposable mirror images of each other are called :

KE of one mole of He at 0°C is

Isomers which can be interconverted through rotation around a single bond are

The kinetic energy of any gas molecule at 0^@C is :

Isomers which can be interconverted through rotation around a single bond are:

K_(e ) " for " PCl_(5)(g) hArr PCl_(3) (g)+Cl_(2)(g) is 0.04 at 250^(@)C. How many moles of PCl_(5) must be added to a 3L flask to obtain a Cl_(2) concentration of 0.15 M

Isomers which can be inter converted through rotation around a single bond are

KCN reacts readily to give a cyanide with

Isomers of propionic acid are

KCN reacts to form cyanide with :

KCN is used for the separation of :

KCN is used for separting

KCN is used for separating:

KCN is used for separating

Isomers have essentially identical :

KCN is highly poisonous while K_(4)[Fe(CN)_(6)] is not. Why ?

KClO_(3) to KCl + O_(2)(unbalanced), If in above reaction 5 moles of KClO_(3) was heated, then find moles of O_(2) produced on completion of reaction.

Isomers have essentially identical.

Isomerism shown by CH_(3)-(CH_(2))_(3)-O-CH_(3) CH_(3)-CH_(2)-O-CH_(2)-CH_(2)-CH_(3) CH_(3)-underset(CH_(3))underset(|)(CH)-O-CH_(2)-CH_(3) is

KClO_3 on heating decomposes to give KCl and O_2 What is the volume of O_2 at N.T.P liberated by 0.1 mole of KClO_3 ?

Isomers are different compounds that have the same

Isomerisom present in CrCl_(3)6H_(2)O is…………..

KClO_(3) overset( "conc. HCl") ( rarr) X_("(g)") + Y_("(g)") X= ? Y= ?

Isomerization of glucose products

Isoomerisms exhibited by [Cr(NH_(3))_(2)(H_(2)O)_(2)Cl_(2)]^(+) are

KCl, KNO_(3) etc. are preferred in a salt bridge because they have equal____.

Isomerism shown by 2,3-dichlorobutane is

KCl is added to Fe(OH)_3 sol?