Q.1 Which of the following alcohols is most acidic?
CH3CH2OH
CH3OH
C6H5OH
(CH3)3COH
Explanation - Phenol (C6H5OH) is more acidic than alcohols because the phenoxide ion is stabilized by resonance.
Correct answer is: C6H5OH
Q.2 What is the functional group present in ethers?
-OH
-O-
-COOH
-CHO
Explanation - Ethers have the general formula R-O-R', where an oxygen atom is connected to two alkyl or aryl groups.
Correct answer is: -O-
Q.3 Which reagent is commonly used for the oxidation of primary alcohols to aldehydes?
PCC
KMnO4
NaBH4
LiAlH4
Explanation - Pyridinium chlorochromate (PCC) oxidizes primary alcohols to aldehydes without further oxidation to carboxylic acids.
Correct answer is: PCC
Q.4 Which of the following compounds will give a positive Fehling's test?
CH3CH2OH
CH3CHO
C6H5OH
CH3OCH3
Explanation - Fehling's test is positive for aldehydes but not for primary alcohols, phenols, or ethers.
Correct answer is: CH3CHO
Q.5 Which of these alcohols will undergo dehydration most easily?
CH3CH2OH
(CH3)3COH
CH3CH2CH2OH
CH3OH
Explanation - Tertiary alcohols dehydrate more easily than primary and secondary alcohols due to the stability of the tertiary carbocation.
Correct answer is: (CH3)3COH
Q.6 What is the IUPAC name of the ether CH3OCH2CH3?
Methoxyethane
Ethoxymethane
Methoxypropane
Ethyl methyl ether
Explanation - The ether is named as an alkoxy derivative of the longest carbon chain: CH3O-CH2CH3 is Methoxyethane.
Correct answer is: Methoxyethane
Q.7 Which phenol is used in the production of Bakelite?
Phenol
Cresol
Catechol
Resorcinol
Explanation - Phenol reacts with formaldehyde to produce Bakelite, a phenol-formaldehyde resin.
Correct answer is: Phenol
Q.8 Alcohols can be oxidized to carboxylic acids using:
PCC
KMnO4
NaBH4
LiAlH4
Explanation - Potassium permanganate (KMnO4) is a strong oxidizing agent that oxidizes primary alcohols to carboxylic acids.
Correct answer is: KMnO4
Q.9 Which of the following is a secondary alcohol?
CH3CH2OH
CH3CHOHCH3
(CH3)3COH
CH3OH
Explanation - A secondary alcohol has the -OH group attached to a carbon atom bonded to two other carbon atoms.
Correct answer is: CH3CHOHCH3
Q.10 Phenols react with bromine water to give:
Yellow precipitate
Red solution
White precipitate
No reaction
Explanation - Phenols undergo bromination to give 2,4,6-tribromophenol, which precipitates as a white solid.
Correct answer is: White precipitate
Q.11 Which alcohol does not react with Lucas reagent at room temperature?
CH3OH
CH3CH2OH
CH3CHOHCH3
(CH3)3COH
Explanation - Primary alcohols like CH3OH react very slowly or not at all with Lucas reagent at room temperature.
Correct answer is: CH3OH
Q.12 What type of reaction converts an alcohol into an alkyl halide?
Oxidation
Substitution
Elimination
Addition
Explanation - Alcohols react with halogen acids to undergo nucleophilic substitution forming alkyl halides.
Correct answer is: Substitution
Q.13 Which compound is known as diethyl ether?
CH3CH2-O-CH2CH3
CH3-O-CH3
CH3CH2OH
CH3CHOHCH3
Explanation - Diethyl ether has two ethyl groups attached to oxygen: CH3CH2-O-CH2CH3.
Correct answer is: CH3CH2-O-CH2CH3
Q.14 Which of the following alcohols can undergo intramolecular dehydration to give an alkene?
CH3CH2OH
CH3CHOHCH3
(CH3)3COH
CH3OH
Explanation - Secondary alcohols like CH3CHOHCH3 dehydrate easily to give alkenes via an E1 mechanism.
Correct answer is: CH3CHOHCH3
Q.15 Phenol reacts with NaOH to form:
Sodium phenoxide
Sodium hydroxide
Benzene
No reaction
Explanation - Phenol is acidic and reacts with NaOH to form the salt sodium phenoxide.
Correct answer is: Sodium phenoxide
Q.16 Which of the following is used as an anesthetic?
CH3CH2OH
C6H5OH
CH3CH2OCH2CH3
CH3OH
Explanation - Diethyl ether (CH3CH2OCH2CH3) was historically used as a general anesthetic.
Correct answer is: CH3CH2OCH2CH3
Q.17 What is the product when phenol reacts with concentrated HNO3?
2-nitrophenol
Phenyl nitrate
Nitrobenzene
2,4,6-trinitrophenol
Explanation - Phenol undergoes electrophilic substitution with nitric acid to form 2,4,6-trinitrophenol (picric acid).
Correct answer is: 2,4,6-trinitrophenol
Q.18 Which alcohol reacts fastest with Lucas reagent?
CH3CH2OH
CH3CHOHCH3
(CH3)3COH
CH3OH
Explanation - Tertiary alcohols react fastest with Lucas reagent due to formation of a stable tertiary carbocation.
Correct answer is: (CH3)3COH
Q.19 Ether cleavage with HI gives:
Alcohol and halide
Two alkyl halides
Aldehyde and alcohol
Carboxylic acid and alcohol
Explanation - Ethers react with HI to cleave the C-O bond, forming two alkyl halides.
Correct answer is: Two alkyl halides
Q.20 Which compound is more acidic, phenol or ethanol?
Phenol
Ethanol
Both equal
Cannot be compared
Explanation - Phenol is more acidic because the phenoxide ion is resonance-stabilized, unlike the ethoxide ion.
Correct answer is: Phenol
Q.21 What is the main product when an alcohol reacts with PCl5?
Alkyl chloride
Alkene
Ether
Ketone
Explanation - Alcohol reacts with PCl5 to replace the -OH group with -Cl, forming an alkyl chloride.
Correct answer is: Alkyl chloride
Q.22 Which reaction converts phenol into an ether?
Williamson synthesis
Friedel-Crafts alkylation
Halogenation
Nitration
Explanation - In the Williamson ether synthesis, phenoxide ion reacts with an alkyl halide to form an ether.
Correct answer is: Williamson synthesis
Q.23 Which of the following is a primary alcohol?
CH3CH2OH
CH3CHOHCH3
(CH3)3COH
CH3OH
Explanation - Primary alcohols have the -OH group attached to a carbon bonded to only one other carbon.
Correct answer is: CH3CH2OH
Q.24 Phenol reacts with bromine in the presence of FeBr3 to give:
2,4,6-tribromophenol
Bromoethanol
Bromobenzene
No reaction
Explanation - Phenol undergoes electrophilic substitution with bromine to give 2,4,6-tribromophenol, a white precipitate.
Correct answer is: 2,4,6-tribromophenol
Q.25 What is the product of dehydration of ethanol with concentrated H2SO4?
Ethene
Ethane
Diethyl ether
Acetaldehyde
Explanation - Ethanol undergoes acid-catalyzed dehydration to form ethene at high temperatures.
Correct answer is: Ethene