MCQ Phenol pharmaceutical organic chemistry 3rd semester B.Pharmacy

MULTIPLE CHOICE QUESTIONS of phenol of Pharmaceutical Organic Chemistry, 3rd semester B.Pharmacy.

1. Phenol is

  • a) Solid
  • b) Crystalline solid
  • c) Gas
  • d) Liquid

Answer- b) Crystalline solid

2. Phenol is stronger acid than water and itself it is

  • a) Weakly basic
  • b) Weakly acidic
  • c) Alkali
  • d) Strong acid

Answer- b) Weakly acidic

3. Phenol undergoes ionisation to become more stable by reacting with

  • a) Positive ions
  • b) Negative ions
  • c) Both a and b
  • d) Neutral atoms

Answer- b) Negative ions

4. Melting point of phenol is relatively high for an aryl compound because of the

  • a) Covalent bonding
  • b) Ionic bonding
  • c) Hydrogen bonding
  • d) All of them

Answer- c) Hydrogen bonding

5.  Phenol reacts readily then benzene, so it is a

  • a) Electrophile
  • b) Nucleophile
  • c) Protophile
  • d) Both a and b

Answer- a) Electrophile

6. Which of the following is used in the manufacture of bakelite?

  • a) Phenol
  • b) Formaldehyde
  • c) Ethyl alcohol
  • d) Both a and b

Answer- d) Both a and b

7. Which of the following is most acidic?

  • a) Benzyl alcohol
  • b) Cyclohexanol
  • c) Phenol
  • d) m-chlorophenol

Answer- d) m-chlorophenol

8. Phenol is less acidic than

  • a) Ethanol
  • b) O-nitrophenol
  • c) O-methyl phenol
  • d) O-methoxy phenol

Answer- b) O-nitrophenol

9. Phenol is more readily soluble in

  • a) NaOH solution
  • b) Dil. HCI
  • c) Both a and b
  • d) NaHCO3

Answer- a) NaOH solution

10. Picric acid forms when phenol reacts with

  • a) Hydrogen
  • b) Nitric acid
  • c) Sulphuric acid
  • d) Formaldehyde

Answer- b) Nitric acid

11. 2,4,6- Tribromo phenol forms when phenol reacts with

  • a) Formaldehyde
  • b) Nitric acid
  • c) Hydrogen
  • d) Bromine

Answer- d) Bromine

12. Phenols are derivative of

  • a) Benzene
  • b) Alkanes
  • c) Alkenese Jogir
  • d) Alkynes

Answer- a) Benzene

13.Phenol can be distinguished from ethanol by the reaction with

  • a) Br₂/water
  • b) Na
  • c) Neutral FeCl3
  • d) All of above

Answer- a) and C)

14. Phenol is better Bronsted acid than cyclohexanol because

  • a) It is a better proton donor
  • b) The cyclohexyl group in an electron donating group by induction, which stabilizes the anion formed in the reaction
  • c) Phenol is able to stabilize the anion formed in the reaction by resonance
  • d) None of above

Answer- c) Phenol is able to stabilize the anion formed in the reaction by resonance

15. Phenol can be prepared by the reaction between

  • a) Aniline and HNO, at 373K
  • b) CH.MgBr and CO, followed by hydrolysis
  • c) CH.SO,Na and NaOH at 623K followed by acidification
  • d) CH₂Cl and NaOH at 373K

Answer- c) CH.SO,Na and NaOH at 623K followed by acidification

16. Choose the correct order related to acidic strength

  • a) Phenol > water > ethyl alcohol
  • b) Ethyl alcohol > water > phenol
  • c) Ethyl alcohol > phenol > water
  •  d) Water > phenol > ethyl alcohol

Answer- a) Phenol > water > ethyl alcohol

17. The distillation of phenol with zinc dust gives

  • a) C6H12
  • b) C6H6
  • c) C6H5 -C6H5
  • d) C6H5-OC6H5

Answer- b) C6H6

18. Treatment of phenol with nitrous acid (NaNO2 + HCI) gives mainly

  • a) p-nitrophenol
  • b) picric acid
  • c) m-nitrophenol
  • d) p-nitrosophenol

Answer- d) p-nitrosophenol

19. Which of the following statements are correct for phenol?

  • a) Phenol is more acidic than phenol
  • b) Phenol is used in the production of melamine plastic
  • c) Phenol gives violet colour with neutral ferric chloride solution
  • d) Phenol when heated with acetyl chloride give phemetole
    • (i) a and b
    • (ii) a and c
    • (iii) c and d
    • (iv) a and d

Answer-(ii) a and c

20. Boiling point of phenols are higher than those of corresponding hydrocarbon and aryl halide because-

  • a) Strong association of molecules by intermolecular hydrogen bonding
  • b) Strong association of molecules by intramolecular hydrogen bonding
  • c) Both (a) and (b)
  • d) None of above

Answer- a) Strong association of molecules by intermolecular hydrogen bonding

21. Choose correct order of acidity for following

  • a) o-cresol > p-cresol > m-cresol
  • b) p-cresol> o-cresol > m-cresol
  • c) m-cresol > p-cresol > o-crèsol
  • d) m-cresol > o-cresol > p-cresol

Answer- c) m-cresol > p-cresol > o-crèsol

22. Phenol recuts with bromine in chloroform at low temperature to give

  • a) m-bromophenol
  • b) mixture of ortho and para-bromophenol
  • c) p-bromo phenol
  • d) 2,4,6-Tribromophenol

Answer- b) mixture of ortho and para-bromophenol

23. Electron withdrawing substituents

  • a) Stabilise the phenoxide ion and increase the acidity of phenol
  • b) Stabilise the phenoxide ion and decrease the acidity of phenol
  • c) Stabilise the phenoxide ion and neutralise the acidity of phenol
  • d) None of above

Answer- a) Stabilise the phenoxide ion and increase the acidity of phenol

24. Sulphonation of phenol at room temperature gives

  • a) p-isomer
  • b) o-isomer
  • c) Both a and b
  • d) None of above

Answer- b) o-isomer

25. Sulphonation of phenol at 370K gives

  • a) p-isomer
  • b) o-isomer
  • c) m-isomer
  • d) Both a and b

Answer- a) p-isomer

26. Which statement is correct relative to Electron releasing group on phenol

  • a) Stabilise the phenoxide ion and increase the acidity
  • b) Destabilise the phenoxide ion and decrease the acidity
  • c) Destabilise the phenoxide ion and increase the acidity
  • d) Stabilise the phenoxide ion and decrease the acidity

Answer- b) Destabilise the phenoxide ion and decrease the acidity

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