Online Test — Alcohols, Phenols and Ethers
20 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 20
Acid-catalysed hydration of 2-methylpropene gives mainly:
2-methylpropan-2-ol
2-methylpropan-1-ol
butan-2-ol
butan-1-ol
Explanation: Markovnikov addition gives the 3° carbocation, so –OH lands on the central carbon: 2-methylpropan-2-ol.
Question 2 of 20
Hydroboration–oxidation of an alkene is:
Markovnikov
anti-Markovnikov
random
oxidative cleavage
Explanation: B2H6 then H2O2/OH– adds –OH to the less substituted carbon (anti-Markovnikov).
Question 3 of 20
A Grignard reagent + methanal, after hydrolysis, gives a:
ketone
tertiary alcohol
primary alcohol
secondary alcohol
Explanation: Methanal (HCHO) gives a primary alcohol with RMgX.
Question 4 of 20
The Lucas test distinguishes alcohols based on:
boiling point
colour with FeCl3
solubility
rate of turbidity (SN1)
Explanation: Turbidity from insoluble alkyl chloride forms fastest for 3° (SN1), slower for 2°, not for 1° at room temperature.
Question 5 of 20
Acidity order of alcohols:
1° > 2° > 3°
3° > 2° > 1°
2° > 1° > 3°
all equal
Explanation: Electron-releasing alkyl groups destabilise alkoxide, so acidity is 1° > 2° > 3°.
Question 6 of 20
Oxidation of a secondary alcohol gives a:
carboxylic acid
ketone
aldehyde
ether
Explanation: A 2° alcohol oxidises to a ketone, which is not easily oxidised further.
Question 7 of 20
Phenol is more acidic than ethanol because:
ethanol is gaseous
phenol is aromatic
phenoxide is resonance-stabilised
phenol has higher mass
Explanation: Delocalisation of the negative charge into the ring stabilises phenoxide, making phenol the stronger acid.
Question 8 of 20
The cumene process yields phenol and:
methanol
benzaldehyde
acetic acid
acetone
Explanation: Cumene hydroperoxide decomposes in acid to phenol and acetone.
Question 9 of 20
Reaction of phenol with CHCl3/NaOH gives:
salicylaldehyde
salicylic acid
picric acid
anisole
Explanation: Reimer–Tiemann reaction via dichlorocarbene gives 2-hydroxybenzaldehyde (salicylaldehyde).
Question 10 of 20
Phenol + CO2 (as phenoxide), then H+, gives (Kolbe):
benzoic acid
salicylic acid
salicylaldehyde
benzoquinone
Explanation: Kolbe's reaction gives 2-hydroxybenzoic acid (salicylic acid).
Question 11 of 20
The strongest acid is:
phenol
p-cresol
p-nitrophenol
cyclohexanol
Explanation: The electron-withdrawing –NO2 at para stabilises phenoxide most, so p-nitrophenol is strongest.
Question 12 of 20
A violet colour with neutral FeCl3 indicates:
an alcohol
an ether
an alkane
a phenol
Explanation: Phenols form a coloured iron complex; alcohols and ethers do not.
Question 13 of 20
Williamson synthesis requires:
alkoxide + 1° halide
alkoxide + 3° halide
two alcohols + heat
phenol + alkene
Explanation: An SN2 reaction needs a primary halide; 3° halides eliminate.
Question 14 of 20
The IUPAC name of C6H5OCH3 is:
phenyl methyl ketone
methoxybenzene
benzyl alcohol
toluene
Explanation: Anisole is named methoxybenzene in IUPAC.
Question 15 of 20
Cleavage of CH3OC2H5 by hot HI (SN2) gives mainly:
C2H5I + CH3OH
two C2H5I
CH3I + C2H5OH
no reaction
Explanation: Iodide attacks the smaller, less hindered methyl group by SN2, giving CH3I and ethanol.
Question 16 of 20
Diethyl ether boils far below butan-1-ol because the ether:
is heavier
is ionic
is aromatic
cannot form intermolecular H-bonds
Explanation: Lacking O–H, ethers cannot self H-bond, so they boil much lower than isomeric alcohols.
Question 17 of 20
In anisole, electrophilic substitution is directed to the:
ortho/para positions
meta position
oxygen
side chain
Explanation: –OCH3 is activating and o/p-directing.
Question 18 of 20
Which alcohol resists oxidation by acidified KMnO4?
ethanol
2-methylpropan-2-ol
propan-2-ol
methanol
Explanation: A 3° alcohol has no H on the C–OH carbon and resists oxidation.
Question 19 of 20
Dehydration of ethanol with conc. H2SO4 at 413 K mainly gives:
ethene
ethanal
diethyl ether
ethanoic acid
Explanation: Lower temperature (~413 K) favours diethyl ether; ~443 K gives ethene.
Question 20 of 20
Bromine water added to phenol gives:
o-bromophenol only
bromobenzene
no reaction
2,4,6-tribromophenol
Explanation: The strongly activated ring undergoes triple substitution to give a white precipitate of 2,4,6-tribromophenol.