94420 + Interview Questions in Chemistry in Class 12

1.	P-P-Pangle in white phosphorous is
Answer» `600^(@)` `900^(@)` `109^(@)28'` `120^(@)` Answer :A

Discussion

2.	P - P - P bond angle in white phosphorous is
Answer» `60^@` `90^@` `120^@` `109^@28^` ANSWER :A

Discussion

3.	P-P linkage is present in
Answer» Pyrophosphoric acid HYPOPHOSPHORIC acid Peroxy PHOSPHORIC acid Metaphosphoric acid Answer :2

Discussion

4.	P overset("Reduction")to Q overset("Dehydration")to R overset("Hydro-chlorination")to S What is P, Q, R, S?
Answer» `P= CH_(3)COOH"" Q= CH_(3)CH_(2)OH` `R= CH_(3)CHO"" S= CH_(3)CH_(2)Cl` `P= CH_(3)CHO"" Q= CH_(3)CH_(2)OH` `R= CH_(2)= CH_(2)"" S= CH_(3)CH_(2)OH` `P= CH_(3)COOH"" Q= CH_(3)CH_(2)OH` `R= CH_(2)= CH_(2)"" S= CH_(3)CH_(2)Cl` `P= CH_(3)CH_(2)Cl"" Q= CH_(3)CH_(2)OH` `R= CH_(2)= CH_(2)"" S= CH_(3)CH_(2)Cl` Solution :`underset("Ethanoic acid")(underset("(P)")(CH_(3)COOH)) underset(LiAlH_(4)H_(2)O)OVERSET("Reduction")to underset("Ethanol")(underset("(Q)")(CH_(3)CH_(2)OH)) overset("Dehydration con" H_(2)SO_(4))underset(473K)to underset("Ethene")(underset("(R)")(CH_(2)=CH_(2))) underset(HCL)overset("Hydrochlorination")to underset("Chloroethane")(underset("(S)")(CH_(3)CH_(2)Cl))`

Discussion

5.	(P) overset(NaH)rarr (Q) uarr overset(CuSO_(4))rarr (R) darr black precipitate, (P) may be
Answer» `SCl_(2)` `PCl_(3)` `NCl_(3)` HCl Answer :A::B

Discussion

6.	[P] overset(Br_(2))to C_(2)H_(4)Br_(2) underset(NH_(3))overset(NaNH_(2))to [Q] underset(Hg^(2+), Delta)overset(20% H_(2)SO_(4))to [R] overset(Zn-Hg // HCl)to [S] The species P, Q, R and S respectively are
Answer» ethene, ETHYNE, ethanal, ethane ethane, ethyne, ethanal, ethene ethene, ethyne, ethanal, ethanol ethyne, ethane, ethene, ethanal. Solution :`[P] overset(Br_(2))to overset(+)C_(2)H_(4)Br_(2) underset(NH_(3))overset(NaNH_(2))to Q underset(Hg^(2+), Delta)overset(20% H_(2)SO_(4))to R underset(HCl)overset(Zn-Hg)to S` P is undergoing `Br_(2)` addition reaction and `Br_(2)` being used in 1 mol. `:.` P is `C_(2)H_(4)` or `CH_(2)=CH_(2)` `underset((P))(H_(2)C=CH_(2))+Br_(2) underset("Addition")overset("Anti")to underset(Br)underset(\|)CH_(2)-overset(Br)overset(\|)CH_(2) underset(underset("Elimination (twice)")(E_(2)))overset(overset(+)Naoverset(ddot)(barNH_(2)) // NH_(3))to underset((Q))(HC -= CH) underset(underset("HYDRATION reaction")(Hg^(2+), Delta))overset(20% H_(2)SO_(4))to CH_(2)=underset(OH)underset(\|)CH overset("Tautomerism")HARR underset((R))(CH_(3)-underset(O)underset(\|\|)C-H) underset(CONC. HCl)overset(Zn-Hg)to underset((S))(CH_(3)CH_(3))`

Discussion

7.	Poverset(H_(2)//Pd-BaSO_(4))toQunderset((ii)dil.HCl)overset((I Con.NaOH))toR+S R and S form benzyl benzoate when treated with each other .Hence P is
Answer» `C_(6)H_(5)CHO` `C_(6)H_(5)CH_(2)OH` `C_(6)H_(5)COCL` `C_(6)H_(5)COOH` SOLUTION :(c) R + S form benzyl BENZOATE on reaction with each other.

Discussion

8.	P underset(2.H_3O^(+))overset(1. CH_3MgBr) to R overset(1. dil. NaOH)underset(2.Delta)to 4-methylpent -3-en-2-one P is
Answer» `Ba(NO_(3))_(2)` `Na_(3)PO_(4)` `CaF_(2)` `Na_(2)SO_(4)` ANSWER :A

Discussion

9.	[P] on treatment with H_(2)CrO_(4)in acetone produced [Q]. [Q] compound upon heating give rise to Acetophenone. The compound [P] is:
Answer» ANSWER :A

Discussion

10.	P-O-P bond is present in
Answer» <P>`H_(4)P_(2)O_(6)` `H_(4)P_(2)O_(5)` Both (A) and (B) None of these Answer :B

Discussion

11.	P-O-P bond is present in :
Answer» METAPHOSPHORIC acid Pyrophosphoric acid Peroxomonophosphoric acid Hypophosphoric acid. Answer :B

Discussion

12.	p-Nitrotoluene on further nitration gives
Answer» SOLUTION :ANOTHER nitro group will be INTRODUCED at the position meta w.r.t. the nitro group already EXISTING and ortho w.r.t. the `CH_(3)^(-)` group. Hence A is the correct choice.

Discussion

13.	p-nitrotoluene can be obtained by:
Answer» TOLUENE`overset("conc. "HNO_(3)+"conc. "H_(2)SO_(4)gt50^(@)C)to` ANSWER :A::C

Discussion

14.	p. Nitrophenol is more acidic than phenol. Explain why?
Answer» SOLUTION :p-Nitrophenol is more ACIDIC than phenol Phenal p-Nitrophenol In case of p-nitrophenol DUE to I EFFECT of -`NO_(2)` group the loss of H-atom as proton from-O-H group is facilitated as compared to phenol.

Discussion

15.	p-Nitrophenol is having lower pK_(a) value than phenol because
Answer» phenol is more acidic than p-nitro phenol. anion of p-nitro phenol is more stablised by resonance than that of phenol. degree of IONISATION of p-nitro phenol is LESS than that of phenol. anion of p-nitro phenol is less STABLE than that of phenol. ANSWER :B

Discussion

16.	p-nitrophenol and o-nitrophenol are separatedby
Answer» Crystallisation Fractional crystallisation DISTILLATION Steam distillation Solution :o-nitro PHENOL the intramolecular hydrogen bonding, while p-nitrophenol has intermolecular hydrogen bonding (comparatively STRONGER). Due to this reason, the boiling point of o-nitrophenol is found QUITE less than that of p-nitrophenol.Hence, o-nitrophenol is steam volatile and can be separated from p-nitrophenol by steam distillation.

Discussion

17.	p- Nitrophenol is a stronger acid than phenol because nitro group is :
Answer» ELECTRON DONATING Electron WITHDRAWING Basic Acidic Answer :B

Discussion

18.	p-nitrophenol and o-nitrophenol are separated by :
Answer» distillation steam distillation crystallization fractional crystallization Solution :p-nitrophenol has more boiling point due to intermolecular hydrogen bonding. Separated by distillation In the o-compound the hydrogen boiling is intramolecular, and so the molecule BEHAVES as a 'single unit'. Hydrogen bonding in the p-compound is intermolecular. Thus, we are DEALING with associated molecules, which behave as a large molecule with high that of the monomer). Since we have assumed that the o-compound has the type of hydrogen bonding SHOWN, this PRESUMABLY is also possible for the p-compound. On the other hand, hydrogen bonding between hydrozyl groups in the p-compound is possible.

Discussion

19.	p-Nitrobenzoic acid has higher K_(a) value than benzoic acid. Give reasons.
Answer» Solution :Higher the `K_(a)`, stronger is the acid. Thus, p-nitrobenzoic acid is a stronger acid than benzoic acid. This is due to the following two reasons: (i) due to -I and -R-effect of the `-NO_(2)` group, the ELECTRON density in the O-H BOND decreases. as a result, O-H bond becomes weak and hence p-nitrobenzoic acid more easily LOSES a PROTON than benzoic acid . (ii) Due to -I and -R-effect of the `NO_(2)` group, dispersal of the -ve charge OCCURS and hence p-nitrobenzoate ion becomes more stable than benzoate ion. .

Discussion

20.	p-Nitroaniline can be obtained by
Answer» SOLUTION :`-SO_(3)H` group PRESENT in o-and p- POSITIONS are easily replaced.

Discussion

21.	p-nitro toluene convert p - nitro benzaldehyde by using
Answer» `KOH + KMnO_(4)` `CrO_(3) " in " (CH_(3)CO)_(2)O` `SnCl_(2) + HCl` PD -`BaSO_(4)+` guinoline Answer :B

Discussion

22.	p-Nitro aniline can be obtained by
Answer» Solution : Here, `-SO_(3)H` GROUP is knocked out. D choice represnts the protective NITRATION of ANILINE

Discussion

23.	p-nitro chlorobenzene undergoes nucleophilic substitution faster than chlorobenzene.
Answer» SOLUTION : p-nitro chlorobenzene undergoes nucleophilic substitution FASTER than chlorobenzene. This is because the anion formed after the ATTACK of nucleophile is stabilised more in case of p-nitro chlorobenzene due to electron withdrawing effect of - `NO_(2)`group.

Discussion

24.	p - Nitro phenol is more acidic than phenol. Explain.
Answer» Solution :This because `-NO_(2)` GROUP has `-I` EFFECT. As a RESULT of it : (a) the LOSS of H atom as proton is facilitated. (b) The phenoxide ion formed after the loss of proton gets stabilised.

Discussion

25.	p-methoxybenzyl bromide reacts faster than p-nitrobenzyl bromide with ethanol to form an ether product. Explain why?
Answer» SOLUTION :It is because of the DIFFERENCE in the STABILITY of carbocations formed in two CASES,

Discussion

26.	p-methoxylbenzyl bromide reacts faster than p-nitrobenzyl bromide with ethanol to form an ether product. Explain, why ?
Answer» Solution : METHOXY GROUP is ELECTRON releasing, therefore, it stabilises carbocation formed by p-methoxybenzyl BROMIDE whereas nitro group being electron withdrawing destabilises carbocation formed by p-nitro BENZYL bromide. That is why p-methoxybenzyl bromide is more reactive than p-nitrobenzyl bromide.

Discussion

27.	Pi - molecular orbitals can result from the overlapping of:
Answer» p-orbitals `sp^2`-orbitals s-orbitals sp-orbitals Answer :A

Discussion

28.	p = K_H. xis the statement of:
Answer» Avogadro's LAW. DALTON's law of partial vapour PRESSURE. RAOULT's law. HENRY's law. Solution : Henry.s law.

Discussion

29.	P is the probability of finding the 1s electron of hydrogen atom in a spherical shell of infinitesimal thickness, dr at a distanc, r from the nucleus. The volume of this shell is 4pi r^(2) dr. The qualitative sketch of the dependence of P on r is
Answer» ANSWER :C

Discussion

30.	P is an alcohl which on heating with Al_(2)O_(3) forms an alkene Q.Q on ozonolysis produces R and S. When the mixture of R and S is heated with NaOH, a redox reaction takes place and a mixture of an acid salt and alcohol is formed. The compound (Q) is :
Answer» `CH_(3)-OVERSET(CH_(3))overset(\|)(C)=CH-CH_(3)` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(C)-CH=CH-CH_(3)` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(C)-CH_(2)-CH=CH_(2)` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(C)-CH=CH_(2)` Answer :D

Discussion

31.	P is an alcohl which on heating with Al_(2)O_(3) forms an alkene Q.Q on ozonolysis produces R and S. When the mixture of R and S is heated with NaOH, a redox reaction takes place and a mixture of an acid salt and alcohol is formed. The compounds R and S are :
Answer» `CH_(3)-OVERSET(CH_(3))overset(\|)(C)O, CH_(2)=O` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(C)-CH=O, CH_(3)CH=O` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(C)-CH=O+CH_(2)=O` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(C)-CH_(2)-CH=O+CH_(2)=O` ANSWER :C

Discussion

32.	P is an alcohl which on heating with Al_(2)O_(3) forms an alkene Q.Q on ozonolysis produces R and S. When the mixture of R and S is heated with NaOH, a redox reaction takes place and a mixture of an acid salt and alcohol is formed. The alcohol (P) is obtained by :
Answer» `H_(3)C-underset(O)underset(\|\|)(C)-CH_(2)-CH_(3)+CH_(3)MGBR` `CH_(3)-overset(CH_(3))overset(\|)(C)-H-CH_(2)-CH=O+CH_(3)MgBr` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(CH)-CH_(2)MgBr+CH_(3)=O` `CH_(3)-underset(CH_(3))underset(\|)overset(CH_(3))overset(\|)(CH)-CH_(2)-COCl+CH_(3)MGCL` ANSWER :C

Discussion

33.	p-hydroxy azobenzene is formed by the reaction :
Answer» HOFMANN rearrangement FRIES migration BENZIDINE rearrangement Diazotisation and COUPLING ANSWER :D

Discussion

34.	p-Dichorobenzene has higher melting point and lowerr solubility than those of o- and m-isomers. Discuss.
Answer» Solution :The p-isomer being more symmetrical fits closely in the crystal lattice and thus has stornger INTERMOLECULAR forces of attraction than those of o- and m-isomers. Since during melting or DISSOLUTION, the crystal lattice breaks, therfore, a larger amount of ENERGY is needed to melt or dissolve the p-isomer than the corresponding o-and m-isomers. in other words, the melting POINT of the p-isomer is higher and it ssolubility lower than the corresponding o- and -isomers.

Discussion

35.	p-dichlorobenzene has highest m.p. than those of ortho and m-isomers?
Answer» Solution :p-dichlorobenzene is SYMMETRICAL, FITS into crystal lattice more readily and has HIGHER MELTING POINT

Discussion

36.	p-Dichlorobenzene has higherm.p. and lower solubility than those ofo -and m-isomers. Discuss.
Answer» SOLUTION :The p-isomer being more symmetrical fits closely in the CRYSTAL LATTICE. It has stronger intermolecular forces of attraction than those ofo - and m-isomers. During melting or dissolution, the crystal lattice BREAKS, therefore, a LARGER amount of energy is needed to melt or dissolve the p-isomer than the correspondingo - and m-isomers. In other words, the melting point of the p-isomer is higher and its solubility lower than the correspondingo - and m- isomers.

Discussion

37.	p-cresol reacts with chloroform in alkaline medium to give the compound A which adds hydrogen cyanide to form, the compound B. The latter on acidic hydrolysis gives chiral carboxylic acid. The structure of the carboxylic acid is
Answer» SOLUTION :

Discussion

38.	p-Cresol reacts with chloroform in alkaline medium to give the compound A which adds hydrogen cyanide to form the compound B. the latter on acidic hydrolysis gives chiral carboxylic acid. The structure of the carboxylic acids is
Answer» Solution :OH group is o,p-directinig and hydrolysis of cyanohydrins gives `alpha`-hydroxy ACIDS. THUS, option (B) is CORRECT.

Discussion

39.	p-cresol reacts with chloroform in alkaline medium to give the compound A which adds hydrogen cyanide to form, the 29. compound B. The latter on acidic hydrolysis gives chiral carboxylic acid. The structure of the carboxylic acid is
Answer» WIDTH="30%"> SOLUTION : ` (##NEET_CHE_DPP_C25_E01_022_S02.png" width="80%">

Discussion

40.	p-chlorotoluene on chlorination in the presence fo FeCl_(3) gives
Answer» ANSWER :A

Discussion

41.	p-Cl-C_(6)H_(4)NH_(2)" and "PhNH_(3)""^(+)Cl^(-) can be distinguished by
Answer» `NAOH` `AgNO_(3)` `LiAlH_(4)` `Zn` Answer :B

Discussion

42.	p-Chloroaniline and anilinium hydrochloride can be distinguished by
Answer» SANDMEYER REACTION `NaHCO_(3)` solution `AgNO_(3)` solution Carbylamine reaction Solution :Both p-chloroaniline and anilinium HYDROCHLORIDE are `1^(@)` AMINES and HENCE cannot be destinguished by carbylamine reaction.

Discussion

43.	p-chloroaniline and anilinium hydrochloride can be distinguished by :
Answer» SANDMEYER reaction `NaHSO_(3)` `AgNO_(3)` CARBYLAMINE test. Answer :B

Discussion

44.	p- chloroaniline and aniline hydrochloride can be distinguished by using
Answer» CARBYLAMINE reaction silver NITRATE solution Barium CHLORIDE solution Any of the above Solution :

Discussion

45.	p-chloroamine and anilinium hydrochloride can be distinguished by
Answer» SANDMEYER REACTION `NaHCO_3` `AgNO_3` CARBYLAMINE test Answer :C

Discussion

46.	p block elements of 6^(th) period are represented as :-
Answer» `[XE] 4F^(14) 5d^(10)6p^(1-6)` `[Xe]5F^(14)6d^(10) 6p^(1-6)` `[Kr] 5f^(14) 5d^(10) 6p^(1-6)` `[Xe]4f^(0) 5d^(10)6p^(1-6)` Answer :A

Discussion

47.	P-benzoquinone is obtained from phenol by
Answer» reduction oxidation acidic hydrolysis alkaline hydrolysis Answer :B

Discussion

48.	p- anisidine can be represented by the forumula
Answer» SOLUTION :p-anisidine is p-methoxy ANILINE.

Discussion

49.	P and Q are isomers of dicarboxyhc acid C_(4)H4O_(4) .Both decolourize Br_(2)//H_(2)O On heating, P forms the cyclic anhydride. Upon treatment with dilute alkaline KMnO_(4), P ass well as Q could produce one or more than one from S. T and U. Compounds formed form P and Q are, respectively.
Answer» OPTICALLY ACTIVE s and optically active pair (T,U) Optically active S and optically INACTIVE pair (T,U) Optcally actve pair (T. U) and optically active S Optically inactive pair (T. U) and optically inactive S Answer :B

Discussion

50.	P and Q are ideal gases which do not react with each other. The mass of one mole of P is four times that of Q. At STP, which of the following are true?
Answer» <P> The. average K.E of MOLECULES of P is EQUAL to that of Q The mass of `1 dm^3` of P is four times that of `1 dm^3` of Q On mixing 1`dm^3` of P with `1 dm^3` of Q the partial pressure of each gas in the mixture will be 0.5 atm The rate of diffusion of P is 4 times less than that of Q Answer :A::B::C

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

P-P-Pangle in white phosphorous is

P - P - P bond angle in white phosphorous is

P-P linkage is present in

P overset("Reduction")to Q overset("Dehydration")to R overset("Hydro-chlorination")to S What is P, Q, R, S?

(P) overset(NaH)rarr (Q) uarr overset(CuSO_(4))rarr (R) darr black precipitate, (P) may be

[P] overset(Br_(2))to C_(2)H_(4)Br_(2) underset(NH_(3))overset(NaNH_(2))to [Q] underset(Hg^(2+), Delta)overset(20% H_(2)SO_(4))to [R] overset(Zn-Hg // HCl)to [S] The species P, Q, R and S respectively are

Poverset(H_(2)//Pd-BaSO_(4))toQunderset((ii)dil.HCl)overset((I Con.NaOH))toR+S R and S form benzyl benzoate when treated with each other .Hence P is

P underset(2.H_3O^(+))overset(1. CH_3MgBr) to R overset(1. dil. NaOH)underset(2.Delta)to 4-methylpent -3-en-2-one P is

[P] on treatment with H_(2)CrO_(4)in acetone produced [Q]. [Q] compound upon heating give rise to Acetophenone. The compound [P] is:

P-O-P bond is present in

P-O-P bond is present in :

p-Nitrotoluene on further nitration gives

p-nitrotoluene can be obtained by:

p. Nitrophenol is more acidic than phenol. Explain why?

p-Nitrophenol is having lower pK_(a) value than phenol because

p-nitrophenol and o-nitrophenol are separatedby

p- Nitrophenol is a stronger acid than phenol because nitro group is :

p-nitrophenol and o-nitrophenol are separated by :

p-Nitrobenzoic acid has higher K_(a) value than benzoic acid. Give reasons.

p-Nitroaniline can be obtained by

p-nitro toluene convert p - nitro benzaldehyde by using

p-Nitro aniline can be obtained by

p-nitro chlorobenzene undergoes nucleophilic substitution faster than chlorobenzene.

p - Nitro phenol is more acidic than phenol. Explain.

p-methoxybenzyl bromide reacts faster than p-nitrobenzyl bromide with ethanol to form an ether product. Explain why?

p-methoxylbenzyl bromide reacts faster than p-nitrobenzyl bromide with ethanol to form an ether product. Explain, why ?

Pi - molecular orbitals can result from the overlapping of:

p = K_H. xis the statement of:

P is the probability of finding the 1s electron of hydrogen atom in a spherical shell of infinitesimal thickness, dr at a distanc, r from the nucleus. The volume of this shell is 4pi r^(2) dr. The qualitative sketch of the dependence of P on r is

P is an alcohl which on heating with Al_(2)O_(3) forms an alkene Q.Q on ozonolysis produces R and S. When the mixture of R and S is heated with NaOH, a redox reaction takes place and a mixture of an acid salt and alcohol is formed. The compound (Q) is :

P is an alcohl which on heating with Al_(2)O_(3) forms an alkene Q.Q on ozonolysis produces R and S. When the mixture of R and S is heated with NaOH, a redox reaction takes place and a mixture of an acid salt and alcohol is formed. The compounds R and S are :

P is an alcohl which on heating with Al_(2)O_(3) forms an alkene Q.Q on ozonolysis produces R and S. When the mixture of R and S is heated with NaOH, a redox reaction takes place and a mixture of an acid salt and alcohol is formed. The alcohol (P) is obtained by :

p-hydroxy azobenzene is formed by the reaction :

p-Dichorobenzene has higher melting point and lowerr solubility than those of o- and m-isomers. Discuss.

p-dichlorobenzene has highest m.p. than those of ortho and m-isomers?

p-Dichlorobenzene has higherm.p. and lower solubility than those ofo -and m-isomers. Discuss.

p-cresol reacts with chloroform in alkaline medium to give the compound A which adds hydrogen cyanide to form, the compound B. The latter on acidic hydrolysis gives chiral carboxylic acid. The structure of the carboxylic acid is

p-Cresol reacts with chloroform in alkaline medium to give the compound A which adds hydrogen cyanide to form the compound B. the latter on acidic hydrolysis gives chiral carboxylic acid. The structure of the carboxylic acids is

p-cresol reacts with chloroform in alkaline medium to give the compound A which adds hydrogen cyanide to form, the 29. compound B. The latter on acidic hydrolysis gives chiral carboxylic acid. The structure of the carboxylic acid is

p-chlorotoluene on chlorination in the presence fo FeCl_(3) gives

p-Cl-C_(6)H_(4)NH_(2)" and "PhNH_(3)""^(+)Cl^(-) can be distinguished by

p-Chloroaniline and anilinium hydrochloride can be distinguished by

p-chloroaniline and anilinium hydrochloride can be distinguished by :

p- chloroaniline and aniline hydrochloride can be distinguished by using

p-chloroamine and anilinium hydrochloride can be distinguished by

p block elements of 6^(th) period are represented as :-

P-benzoquinone is obtained from phenol by

p- anisidine can be represented by the forumula

P and Q are isomers of dicarboxyhc acid C_(4)H4O_(4) .Both decolourize Br_(2)//H_(2)O On heating, P forms the cyclic anhydride. Upon treatment with dilute alkaline KMnO_(4), P ass well as Q could produce one or more than one from S. T and U. Compounds formed form P and Q are, respectively.

P and Q are ideal gases which do not react with each other. The mass of one mole of P is four times that of Q. At STP, which of the following are true?