Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.	Phenylmethanol can be prepared by reducing the benzaldehyde with :
Answer» `CH_(3)Br` `ZN` and `HCI` `CH_(3)Br` and `Na` `CH_(3)I` and `Mg` ANSWER :B

2.	Phenylhydrazine can be used to test for
Answer» CARBOXYL group. carbonyl group. alcoholic group. nitrile group. Answer :B

3.	Phenyl methyl ether reacts with HI to give phenol and methyl iodide and not iodobenzene and methl alcohol. Why?
Answer» Solution :Protonation of phenyl methyl ether (anisole) gives oxononium ion. In this ion, `O-CH_(3)` bond is weaker than `O-C_(6)H_(5)` bond which has some double bond character DUE to resonance between the lone pair of electrons on the oxygen atom and the `SP^(2)`-HYBRIDIZED carbon atom of the phenyl ring. therefore, ATTACK by `I^(-)` ion exclusively BREAKS the weaker `O-CH_(3)` bond forming methyl iodide and phenol.

4.	Phenylacetylene on treatment with HgSO_(4)//H_(2)SO_(4), H_(2)O produces
Answer» acetophenone phenylacetaldehyde phenylacetic acid 1- phenylethanol Answer :A

5.	Phenyl salicylate is otherwise knows as _____
Answer» ANSWER :SALOL

6.	Phenyl methanal is reacted with concentrated NaOH to give two products X and Y. X reacts with metallic sodium to liberate hydrogen X and Y are
Answer» sodiumbenzoate and phenol SODIUM BENZOATE and PHENYL METHANOL phenyl methanol and sodium benzoate none of these Solution :

7.	Phenyl isocyanides are prepared from which of the following reactions ?
Answer» Rosenmund's REACTION Carbylamine reaction Reimer-Tieman reaction Wurtz reaction. Solution :Carbylamine reaction is also USED for detection of p-amino group in ORGANIC compounds.

8.	Phenyl isocynanides are preapred from which of the following reactions
Answer» ROSENMUND's REACTION Carbylamine reaction Reimer-Tiemann reaction Wurtz reaction. SOLUTION :

9.	Phenyl isocyanides are prepared from which of the following reaction?
Answer» ROSENMUND's REACTION CARBYLAMINE reaction Reimer-Tiemann reaction WURTZ reactions Answer :B

10.	Phenyl isocynaide is prepared from aniline by:
Answer» Rosenmud's REACTION Reimer-Tiemann reaction Kolbe's reaction Wurtz reaction

11.	Phenyl isocyanides are prepared from which of the following reaction ?
Answer» Rosenmund's reaction Carbylamine reaction Reimer-Tiemann reaction Wurtz reaction Solution :Both aliphatic and aromatic primary amines react with CHLOROFORM and alc. KOH to give isocyanides or carbylamines and the reaction is known as carbylamine reaction. `C_(6)H_(5)NH_(2)+CHCl_(3)+underset((alc.))(3KOH)to underset("PHENYL ISOCYANIDE")(C_(6)H_(5)NC)+3KCl+3H_(2)O`

12.	Phenyl isocyanides are prepared by
Answer» ROSENMUND's REACTION CARBYLAMINE reaction Reimer-Tiemann reaction WURTZ reaction Solution :Carbylamine reaction

13.	Phenyl isocyanide on reduction with hydrogen and Raney nickel gives____
Answer» SOLUTION :N-methylaniline (N-methylbenzenamine).

14.	Phenyl isocyanide is prepared by heating CHCl_(3) with :
Answer» ANSWER :A

15.	Phenyl ethane on oxidation produces
Answer» <P>phthalic acid p - ethenyl BENZOIC acid benzoic acid SALICYLIC acid ANSWER :C

16.	Phentole reacts with HI to give
Answer» iodobezene and ethanol phenol ethyl IODIDE ethyl iodide and BENZENE all of these Solution :`(CH_3)_3C-CH_2Br` (Neophentyl bromide) is most sterically HINDERED alkyl halide and HENCE LEAST reacitve.

17.	Phenoxide ion is morestable than phenol due to the _______.
Answer» resonating structureof benzene RING DELOCALISATION of POSITIVE charge in phenoxide ION delocalisation of negativecharge in phenoxide ion all of these ANSWER :C

18.	Phenolunderset(dust)overset(Zn)toX underset("Anhyd. "AlCl_(3))overset(CH_(3)Cl)toY underset(KMnO_(4))overset(Alk.)toZ The product Z is
Answer» benzaldehyde benzoic ACID benzene toluene Solution :`C_(6)H_(5)OH underset("dust")overset(ZN)to C_(6)H_(6) underset("Anhyd. "AlCl_(3))overset(CH_(3)Cl)to C_(6)H_(5)CH_(3)overset("Alk. "KMKnO_(4))to underset("Benzoic acid")(C_(6)H_(5)COOH)`.

19.	PhenolundersetDeltaoverset"Zn"to(A)underset(conc. H_2SO_4 "at" 27^@C)overset(conc. HNO_3)to (B)overset(Fe+HCl)to(C ) In above reaction ,compound A,B, C are
Answer» BENZENE, benzene sulphoric ACID, aniline benzene, TRINITROBENZENE, aniline benzene DINITROBENZENE, aniline benzene, NITROBENZENE, aniline Answer :D

20.	"Phenol"underset("dust")overset(Zn)to'X'underset("anhy"AlCl_(3))overset(CH_(3)Cl)toYunderset(KMnO_(4))overset("alk")toZ the product Z is _________.
Answer» benzaldehyde benzoic acid benzone toluene Answer :B

21.	Phenols turn blue litmus red
Answer» ANSWER :T

22.	Phenols on treatment with chloroform in the presence of aqueous sodium hydroxide or potassium hydroxide solution give hydroxy aldehydes. In this reaction, the formyl group is directed to ortho position. But if one of the ortho position is occupied then para product is formed. The reaction is electrophilic substitution reaction. What is the name and the structure of the final product formed.
Answer» SOLUTION :

23.	Phenols on treatment with chloroform in the presence of aqueous sodium hydroxide or potassium hydroxide solution give hydroxy aldehydes. In this reaction, the formyl group is directed to ortho position. But if one of the ortho position is occupied then para product is formed. The reaction is electrophilic substitution reaction. What is the intermediate of the reaction if we use carbon tetrachloride in place of chloroform?
Answer» SOLUTION :

24.	Phenols on treatment with chloroform in the presence of aqueous sodium hydroxide or potassium hydroxide solution give hydroxy aldehydes. In this reaction, the formyl group is directed to ortho position. But if one of the ortho position is occupied then para product is formed. The reaction is electrophilic substitution reaction. Write the reaction with p cresol.
Answer» SOLUTION :

25.	Phenols on treatment with chloroform in the presence of aqueous sodium hydroxide or potassium hydroxide solution give hydroxy aldehydes. In this reaction, the formyl group is directed to ortho position. But if one of the ortho position is occupied then para product is formed. The reaction is electrophilic substitution reaction. What is the electrophile in the reaction?
Answer» SOLUTION :DICHLOROCARBENE `C Cl_(2)`

26.	Phenols on treatment with chloroform in the presence of aqueous sodium hydroxide or potassium hydroxide solution give hydroxy aldehydes. In this reaction, the formyl group is directed to ortho position. But if one of the ortho position is occupied then para product is formed. The reaction is electrophilic substitution reaction. What is the name of the reaction?
Answer» SOLUTION : Reimer-Tiemann REACTION.

27.	Phenols on exposureto light and airgetsoxidised to ________.
Answer» QUININES QUINONES QUINOLS all of these ANSWER :B

28.	Phenols occur in_______
Answer» COAL TAR WOOD tar PETROLEUM distillates all of these ANSWER :D

29.	Phenols are more acidic than aliphatic alcohols because
Answer» phenoxide ION is STABILISED by resonance phenols are more SOLUBLE in POLAR solvents phenoxide ion do not have resonance alcohols do not loose H-atom at all Answer :A

30.	Phenols does not protonation reactions readily-Give reason.
Answer» Solution :In Phenol, the lone PAIR of electron on the oxygen ATOM are delocalised due to RESONANCE, HENCE are not easily available for protonation.

31.	Phenols are more acidic than alcohols. Write the structure and IUPAC name of the above product.
Answer» SOLUTION :2,4,6-Trinitrophenol

32.	Phenols are more acidic than alcohols. Name the product obtained when phenol is treated with chloroform in the presence of NaOH.
Answer» SOLUTION :SALICYLALDEHYDE

33.	Phenols are more acidic than alcohols. Name the above reaction.
Answer» SOLUTION :Reimer-Teimann REACTION

34.	Phenols are more acidic than alcohols. Ethanol and propane have comparable molecular masses but boiling points differ widely. Which of them has highes boiling point? Substantiate your answer.
Answer» Solution :Ethanol has HIGHER boiling point because its molecules are associated by INTERMOLECULAR HYDROGEN BONDING.

35.	Phenols are more acidic than alcohols due to (a)In phenols,- OH is attached to sp^(2)hybridised carbon but in alcohols , -OH is attached to sp^(3)hybridised carbon (b) Phenoxide ion is more stable than alkoxide due to resonance (c)Phenoxide ion is more stable than phenol
Answer» only a only B only C a,b, and c ANSWER :D

36.	Phenols are converted into their salts by aqueous NaOH but not by aqueous bicarbonates. The salts are converted into the free phenols by aqueous mineral acids, carboxylic acid or carbonic acids. Most phenols have K_(a) value of about 10^(-10), and are tremondously more acidic than alcohols. The difference in acidity are due to difference in stablities of reactants and products. Phenol and phenoxide ions contain benzene ring and therefore must be hybrid of Kekuley structures Being basic, oxygen can share more than a pair of electron with the ring. Since energy must be supplied to separate opposite charge, the structure of phenols should contain more energy. The net effect of reasonance is therefore to stablise the phenoxideion to a greater extent than the phenol and thus to shift the equilibrium towards ionization and make K_(a) larger than for an alcohol. Choose the correct statement:
Answer» Phenol GIVES effervesence with `NaHCO_(3)` `Picric acid is weaker acid than CARBONIC acid Picric acid gives effervesence with `NaHCO_(3)` SOLUTION :N//A

37.	Phenols are converted into their salts by aqueous NaOH but not by aqueous bicarbonates. The salts are converted into the free phenols by aqueous mineral acids, carboxylic acid or carbonic acids. Most phenols have K_(a) value of about 10^(-10), and are tremondously more acidic than alcohols. The difference in acidity are due to difference in stablities of reactants and products. Phenol and phenoxide ions contain benzene ring and therefore must be hybrid of Kekuley structures Being basic, oxygen can share more than a pair of electron with the ring. Since energy must be supplied to separate opposite charge, the structure of phenols should contain more energy. The net effect of reasonance is therefore to stablise the phenoxideion to a greater extent than the phenol and thus to shift the equilibrium towards ionization and make K_(a) larger than for an alcohol. Which of the following is more stable:
Answer» Both Unpredictable Solution :N//A

38.	Phenols are converted into their salts by aqueous NaOH but not by aqueous bicarbonates. The salts are converted into the free phenols by aqueous mineral acids, carboxylic acid or carbonic acids. Most phenols have K_(a) value of about 10^(-10), and are tremondously more acidic than alcohols. The difference in acidity are due to difference in stablities of reactants and products. Phenol and phenoxide ions contain benzene ring and therefore must be hybrid of Kekuley structures Being basic, oxygen can share more than a pair of electron with the ring. Since energy must be supplied to separate opposite charge, the structure of phenols should contain more energy. The net effect of reasonance is therefore to stablise the phenoxideion to a greater extent than the phenol and thus to shift the equilibrium towards ionization and make K_(a) larger than for an alcohol. Consider the following curves:
Answer» CURVE A represents the ionisation of ALCOHOL Curve B REPRESENT the ionisation of Phenols Curve A represents the ionisation of phenol None Solution :N//A

39.	Phenols are converted into their salts by aqueous NaOH but not by aqueous bicarbonates. The salts are converted into the free phenols by aqueous mineral acids, carboxylic acid or carbonic acids. Most phenols have K_(a) value of about 10^(-10), and are tremondously more acidic than alcohols. The difference in acidity are due to difference in stablities of reactants and products. Phenol and phenoxide ions contain benzene ring and therefore must be hybrid of Kekuley structures Being basic, oxygen can share more than a pair of electron with the ring. Since energy must be supplied to separate opposite charge, the structure of phenols should contain more energy. The net effect of reasonance is therefore to stablise the phenoxideion to a greater extent than the phenol and thus to shift the equilibrium towards ionization and make K_(a) larger than for an alcohol. Which of the following is strongest acid?
Answer» `H_(2)CO_(3)` `CH_(3)-OH` `CH_(3)-CH_(2)-OH` Solution :N//A

40.	Phenols are more acidic than alcohols and CH_(3)NO_(2) because
Answer» which is the conjugate base of phenol is more stable than `Coverset(Ө)H_(2)-NO_(2)` In the phenoxide , the negative charge is on OXYGEN atom having greater UNOCCUPIED surface volume than in `Coverset(Ө)H_(2)-NO_(2)` where the -ve charge is on a LESSER unoccupied surface volume of carbon thereby making Solution : isresonance stabilized , while in `R-O^(Ө)` DUE to +I effect the `R-O^(Ө)` is destabilized . The conjugate base of `CH_(3)NO_(2)` is `overset(Ө)CH_(2)-NO_(2)` which is RESONANCE sbabilized out of `-underset(..)overset(..)O-H` group whose conjugate base is `-O^(Ө)` and `-underset(\|)overset(\|)C^(Ө)` because the charge density is less in `-O^(Ө)` than in`-underset(\|)overset(\|)C^(Ө)` due to greater surface volume available on `-O^(Ө)` than in `-underset(\|)overset(\|)C^(Ө)` is more acidic than ROH and `CH_(3)NO_(2)` . Hence choices (a),(b) and (d) are correct while (c) is incorrect.

41.	Phenols and alcohols have both the same functional group (-OH) but phenols are stronger acids than alcohols. This is mainly due to the reason that the phenoxide ion (C_(6)H_(5)O^(Ɵ)) left after the release of H^(+) ion in phenol is resonance stabilised while the alkoxide ion (RO^(Ɵ)) in alcohols does not show similar characteristics. The electron withdrawing groups tend to increase the acidic strengths of phenols while electron releasing groups tend to decrease it. the effect of both types of groups is more pronounced when present at the para position than when these are present at the ortho position in the ring. However, their effect at the meta position is relatively very small. Which of the following is the strongest acid ?
Answer» `FCH_(2)CH_(2)CH_(2)CH_(2)OH` `FCH_(2)CH_(2)CH_(2)OH` `CH_(3)CH_(2)CHFCH_(2)OH` `CH_(3)CH_(2)CF_(2)CH_(2)OH` Solution :It is the strongest acid due to the presence of TWO electron withdrawing F atom at `C_(2)` atom.

42.	Phenols and alcohols have both the same functional group (-OH) but phenols are stronger acids than alcohols. This is mainly due to the reason that the phenoxide ion (C_(6)H_(5)O^(Ɵ)) left after the release of H^(+) ion in phenol is resonance stabilised while the alkoxide ion (RO^(Ɵ)) in alcohols does not show similar characteristics. The electron withdrawing groups tend to increase the acidic strengths of phenols while electron releasing groups tend to decrease it. the effect of both types of groups is more pronounced when present at the para position than when these are present at the ortho position in the ring. However, their effect at the meta position is relatively very small. The stronger acid among the following is
Answer» o-methoxyphenol p-methoxyphenol m-methoxyphenol phenol. Solution :METHOXY GROUP `(-OCH_(3))` at the PARA position has minimum acid weakening effect.

43.	Phenols and alcohols have both the same functional group (-OH) but phenols are stronger acids than alcohols. This is mainly due to the reason that the phenoxide ion (C_(6)H_(5)O^(Ɵ)) left after the release of H^(+) ion in phenol is resonance stabilised while the alkoxide ion (RO^(Ɵ)) in alcohols does not show similar characteristics. The electron withdrawing groups tend to increase the acidic strengths of phenols while electron releasing groups tend to decrease it. the effect of both types of groups is more pronounced when present at the para position than when these are present at the ortho position in the ring. However, their effect at the meta position is relatively very small. The acidic strength increases in the order
Answer» p-Nitrophenol `lt` m-Nitrophenol `lt` o-Nitophenol p-Nitrophenol `lt` o-Nitrophenol `lt` m-Nitrophenol m-Nitrophenol `lt` o-Nitrophenol `lt` p-Nitrophenol o-Nitropheno `lt` m-Nitrophenol `lt` p-Nitrophenol. Solution :It Is the CORRECT INCREASING order of ACIDIC STRENGTH.

44.	Phenols and alcohols have both the same functional group (-OH) but phenols are stronger acids than alcohols. This is mainly due to the reason that the phenoxide ion (C_(6)H_(5)O^(Ɵ)) left after the release of H^(+) ion in phenol is resonance stabilised while the alkoxide ion (RO^(Ɵ)) in alcohols does not show similar characteristics. The electron withdrawing groups tend to increase the acidic strengths of phenols while electron releasing groups tend to decrease it. the effect of both types of groups is more pronounced when present at the para position than when these are present at the ortho position in the ring. However, their effect at the meta position is relatively very small. The increasing order of reactivity of 1^(@), 2^(@) and 3^(@) alcohols towards sodium metal is
Answer» `1^(@) lt 2^(@) lt 3^(@)` `1^(@) lt 3^(@) lt 2^(@)` `3^(@) lt 2^(@) lt 1^(@)` `2^(@) lt 1^(@) lt 3^(@)` Solution :It involves the CLEAVAGE of `O-H` BOND which is easiest in `1^(@)` ALCOHOLS and most DIFFICULT in `3^(@)` alcohols.

45.	Phenols and alcohols are respectively ________
Answer» NEUTRAL and BASIC basic and ACIDIC acidic and basic acidicand neutral ANSWER :D

46.	Phenolphthalein shows ____ in acid medium:
Answer» RED COLOUR yellow colour Pink colour No colour Answer :D

47.	Phenolphthalein is not suitable for the titration of
Answer» `NaOH` vs `(COOH)_(2)` KOH vs `H_(2)SO_(4)` `K_(2)CO_(3)` vs HCl None of these Answer :D

48.	Phenolphthalein is most suitable indicator for the titration of
Answer» `CH_(3)COOH and NH_(4)OH` `CH_(3)COOH and NaOH` `HCl and NH_(4)OH` `H_(2)CO_(3) and NH_(4)OH` ANSWER :B

49.	Phenolphthalein is not a good indicator for titrating:
Answer» NAOH against OXALIC ACID FERROUS sulphate against `KMnO_4` NaoH against HCl NaoH against `H_2SO_4` Answer :B

50.	Phenol upon distiliation with zinc dust gives :
Answer» Benzene Benzaldehyde Benzoic acid Benzophenone. Answer :A