Free Phenols MCQs with Answers
63 Phenols MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Phenols contain a hydroxyl group directly bonded to an aromatic ring, making them more acidic than alcohols because the phenoxide ion is resonance-stabilised. Reactions include ionisation with bases, electrophilic substitution, bromination, nitration and oxidation, with attention to the difference between phenols and aliphatic alcohols.
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- A. Due to presence of resonance in phenol
- B. Due to the absence of resonance in alcohol
- C. Both Options A and B are correct
- D. Because in phenol, hydrogen is attached to oxygen
Explanation: The answer is Both Options A and B are correct. Phenol is more acidic than alcohol because of two reasons: The presence of resonance in…
Correct answer: Both Options A and B are correct- A. Alcohol
- B. Carboxylic acids
- C. Esters
- D. Amines
Explanation: Acetyl chloride, CH3COCl , which is a derivative of carboxylic acid but more reactive, will react with phenol in the presence of NaOH to…
Correct answer: Esters- A. Ethoxide ion
- B. Tertiary alkoxide ion
- C. Secondary anion
- D. Phenoxide ion
Explanation: in phenoxide ion Oxygen has delocalised-ve charge.it is highly electronegative in nature and stabilised by resonance
Correct answer: Phenoxide ion- A. Picric acid
- B. Benzene
- C. Cresol
- D. Carbolic acid
Explanation: Option B is correct as Phenol gives out a proton and forms phenoxy anion.
Correct answer: Benzene- A. Hydrogenation
- B. Reaction with formaldehyde
- C. Nitration
- D. Halogenation
Explanation: Option A is correct as Phenol is a benzene ring with an OH group bonded to one carbon, if we "hydrogenate" the ring, the carbons will use…
Correct answer: Hydrogenation- A. 4-5
- B. 3-5
- C. 2-4
- D. 5-6
Explanation: The solution of phenol in water has a pH of about 5-6 ( depending upon its concentration ).
Correct answer: 5-6- A. H2 gas
- B. CO2 gas
- C. O2
- D. None of these options are correct
Explanation: None of these options are correct. Phenols, which are aromatic compounds containing a hydroxyl group (-OH) directly attached to an…
Correct answer: None of these options are correct- A. Coke
- B. Pitch
- C. Aromatic compounds
- D. Coal tar
Explanation: Phenol was first obtained from Coal tar Phenol was initially obtained from coal tar.
Correct answer: Coal tar- A. Carbonic acid
- B. Carbolic acid
- C. Acetic acid
- D. Hydroxy acid
Explanation: Carbonic acid: H2CO3 Acetic acid: CH3COOH (ethanoic acid)Carbolic acid: C6H5OH (phenol)Hydroxy acid: a type of acid found in natural foods
Correct answer: Carbolic acid- A. Dense
- B. Hard
- C. Deliquescent
- D. Intermittent
Explanation: Phenol reacts with moisture in the air to give its smell.Phenol is colorless, crystalline solid, and also deliquescent.
Correct answer: Deliquescent- A. Picric acid
- B. Benzene
- C. Cresol
- D. Carbolic acid
Explanation: When phenol is heated with zinc it undergoes a reduction reaction and benzene is formed.
Correct answer: Benzene- A. Coke
- B. Pitch
- C. Aromatic compounds
- D. Coal tar
Explanation: Phenol was first obtained from coal tar, which is a byproduct of the coal gasification process.
Correct answer: Coal tar- A. Ortho hydroxy benzene sulphonic acid
- B. Meta hydroxy benzene sulphonic acid
- C. Ortho and para hydroxy benzene sulphonic acid
- D. Para hydroxy benzene sulphonic acid
Explanation: Explanation:This product is formed in the reaction of phenol with concentrated sulfuric acid.
Correct answer: Ortho and para hydroxy benzene sulphonic acid- A. Br2/H2O
- B. FeSO4
- C. Cl2/H2O
- D. FeCl3
Explanation: Explanation:An aqueous solution of phenol reacts with bromine water to give white ppt of 2,4,6-tribromophenol .
Correct answer: Br2/H2O- A. 1.2 x 10^-10
- B. 1.2 x 10^10
- C. 1.3 x 10^10
- D. 1.3 x 10^-10
Explanation: A is incorrect.B is incorrect.C is incorrect.D is correct as disassociation constant of phenol is 1.3 x10-10 (fact)
Correct answer: 1.3 x 10^-10- A. Picric acid
- B. Nitro phenol
- C. Benzoic acid
- D. Malonic acid
Explanation: Picric acid is 2,4,6-trinitrophenol. Picric acid has a structure consisting of a phenolic ring with three nitro groups (-NO2) attached…
Correct answer: Picric acid- A. 2,4,6-tribromophenol
- B. 2-bromophenol
- C. 4-bromophenol
- D. Phenol
Explanation: Since the OH group has an electron donating effect, it is an ortho-para director. The following reaction occurs:
Correct answer: 2,4,6-tribromophenol- A. A
- B. B
- C. C
- D. D
Explanation: Carbons are numbered according to the placement of the -OH group. The carbon to which the OH group is attached is C1.
Correct answer: B- A. Phenol
- B. Ether
- C. Ethanol
- D. Methanol
Explanation: The antiseptic properties of phenol were used by Sir Joseph Lister (1827-1912).Phenol was one of the earliest disinfectants and…
Correct answer: Phenol- A. 1,3,6-Trinitrophenol
- B. m-Nitrophenol
- C. Tartaric acid
- D. Picric acid
Explanation: Picric acid, also called 2,4,6-trinitrophenol, is a pale yellow, odorless, crystalline solid that has been used as a military explosive…
Correct answer: Picric acid