Alcohols are organic compounds containing
A –COOH group
B –CHO group
C –OH group attached to sp³ carbon
D –OH group attached to sp² carbon
Alcohols have hydroxyl group bonded to saturated carbon.
Phenols differ from alcohols because the –OH group in phenols is attached to
A sp³ carbon
B sp² carbon of benzene ring
C carbonyl carbon
D aliphatic carbon
Phenols have –OH directly attached to aromatic ring.
Which compound is a phenol
A ethanol
B benzyl alcohol
C phenol
D methanol
–OH group is directly attached to benzene ring.
Order of acidity is
A alcohol > phenol > water
B water > alcohol > phenol
C phenol > water > alcohol
D water > phenol > alcohol
Phenoxide ion is resonance stabilised.
Phenol is more acidic than alcohol because
A inductive effect
B resonance stabilisation of conjugate base
C hydrogen bonding
D steric effect
Phenoxide ion is stabilised by resonance.
Alcohols are weaker acids than water due to
A −I effect
B +I effect of alkyl group
C resonance
D steric hindrance
Alkyl group donates electrons, destabilising alkoxide ion.
Which alcohol is most acidic
A methanol
B ethanol
C isopropanol
D tert-butanol
Least +I effect, hence more acidic.
Reaction of alcohol with sodium metal gives
A ether
B alkene
C sodium alkoxide + H₂
D aldehyde
Alcohol behaves as weak acid.
Which reagent converts alcohol into alkyl chloride
A NaCl
B SOCl₂
C KOH
D AgNO₃
Thionyl chloride replaces –OH by –Cl.
Lucas test distinguishes alcohols based on
A oxidation rate
B dehydration rate
C turbidity due to alkyl chloride formation
D ester formation
Rate depends on carbocation stability.
Lucas test gives immediate turbidity with
A primary alcohol
B secondary alcohol
C tertiary alcohol
D phenol
Tertiary carbocation forms fastest.
Oxidation of primary alcohol with PCC gives
A carboxylic acid
B aldehyde
C ketone
D ester
PCC prevents over-oxidation.
Oxidation of secondary alcohol gives
A aldehyde
B acid
C ketone
D ester
Secondary alcohol oxidises to ketone.
Tertiary alcohol on oxidation gives
A aldehyde
B ketone
C acid
D no reaction
No α-hydrogen available.
Dehydration of alcohol gives
A alkane
B alkene
C ether
D ester
Elimination of water occurs.
Dehydration of tertiary alcohol proceeds via
A E2
B SN2
C E1
D free radical
Stable carbocation formation.
Order of dehydration of alcohols is
A 1° > 2° > 3°
B 2° > 1° > 3°
C 3° > 2° > 1°
D all equal
Carbocation stability governs rate.
Phenol does not give Lucas test because
A –OH group is acidic
B C–O bond has partial double bond character
C steric hindrance
D resonance is absent
–OH cannot be replaced easily.
Phenol reacts with NaOH to give
A sodium alkoxide
B sodium phenoxide
C ether
D alcohol
Phenol is acidic enough to react with NaOH.
Alcohols do not react with NaOH because
A they are neutral
B they are strong acids
C alkoxide ion is unstable
D NaOH is weak base
Alcohols are weaker acids than water.
Kolbe reaction of phenol gives
A salicylic acid
B benzoic acid
C anisole
D phenyl acetate
Carboxylation of sodium phenoxide.
Reimer–Tiemann reaction of phenol introduces
A –COOH
B –CHO
C –CH₃
D –NO₂
Ortho-formylation of phenol.
Bromination of phenol in water gives
A bromobenzene
B mono-bromophenol
C di-bromophenol
D tri-bromophenol
Phenol is strongly activating.
Phenol is strongly o,p-directing due to
A −I effect
B +R effect
C steric effect
D hydrogen bonding
Lone pair donation increases electron density.
Ether is characterised by functional group
A R–OH
B R–O–R′
C R–CO–R′
D R–COOH
Oxygen atom between two alkyl/aryl groups.
Ethers are generally prepared by
A dehydration of alcohols
B oxidation of alcohols
C reduction of acids
D nitration
Acid-catalysed intermolecular dehydration.
Williamson synthesis involves reaction of
A alcohol + alcohol
B alkyl halide + alkoxide
C alkene + alcohol
D phenol + acid
SN2 mechanism.
Williamson synthesis does not work well with
A primary halide
B methyl halide
C secondary halide
D tertiary halide
Elimination dominates over substitution.
Anisole is
A phenol
B ether
C aldehyde
D ketone
Methoxybenzene is an ether.
Ethers are relatively inert because
A C–O bond is weak
B oxygen is electronegative
C no active hydrogen
D resonance stabilisation
No acidic hydrogen present.
Cleavage of ethers occurs with
A NaOH
B H₂SO₄
C HI or HBr
D KMnO₄
Strong acids cleave C–O bond.
Ether cleavage with excess HI gives
A alcohol
B ether
C alkyl iodide + alcohol
D two alkyl iodides
Both sides are cleaved.
In ether cleavage, tertiary alkyl group reacts via
A SN2
B SN1
C E2
D free radical
Tertiary carbocation forms.
Primary alkyl ether cleavage follows
A SN1
B E1
C SN2
D radical
Less steric hindrance.
Aromatic ether undergoes cleavage at
A Ar–O bond
B alkyl–O bond
C both bonds
D none
Ar–O bond is stabilised by resonance.
Which ether reacts fastest with HI
A diethyl ether
B methyl tert-butyl ether
C anisole
D diphenyl ether
Tertiary group favours SN1.
Ether does not react with
A HI
B HBr
C Na metal
D PCl₅
No acidic hydrogen present.
Phenyl ether undergoes electrophilic substitution at
A meta position
B ortho and para positions
C para only
D meta and para
–OR group is o,p-directing.
Which compound is least acidic
A phenol
B water
C ethanol
D methanol
Strong +I effect reduces acidity.
Reaction of alcohol with carboxylic acid gives
A ether
B ester
C aldehyde
D ketone
Esterification reaction.
Esterification is catalysed by
A NaOH
B HCl
C conc. H₂SO₄
D NH₃
Acts as acid catalyst and dehydrating agent.
Which compound gives violet colour with FeCl₃
A ethanol
B phenol
C ether
D aldehyde
Phenols form coloured complexes.
Phenol on heating with zinc dust gives
A benzene
B phenyl chloride
C anisole
D benzoic acid
Reduction removes –OH group.
Alcohols form hydrogen bonds because of
A oxygen atom
B hydrogen atom
C O–H bond
D polarity
Polar O–H bond enables H-bonding.
Boiling point of alcohols is higher than ethers due to
A molecular mass
B hydrogen bonding
C polarity
D resonance
Intermolecular H-bonding raises BP.
Which alcohol has highest boiling point
A methanol
B ethanol
C propanol
D butanol
Higher molecular mass increases BP.
Ether is less soluble in water than alcohol because
A higher molecular weight
B lack of hydrogen bonding
C steric hindrance
D polarity
No –OH hydrogen for bonding.
Which compound reacts with NaOH
A ethanol
B ether
C phenol
D methanol
Phenol is acidic.
Which reaction converts phenol to ether
A Kolbe reaction
B Williamson synthesis
C Reimer–Tiemann
D Lucas test
Phenoxide reacts with alkyl halide.
Correct statement is
A Alcohols are stronger acids than phenols
B Phenols are weaker acids than alcohols
C Ethers are generally inert compounds
D Phenols do not undergo electrophilic substitution
Ethers show limited reactivity.