a) -OH
b) -COOH
c) -CHO
d) -C=O
Answer: c) -CHO
Explanation: The functional group of aldehydes is -CHO, which
consists of a carbonyl group (C=O) attached to a hydrogen atom.
a) Acetone
b) Formaldehyde
c) Benzophenone
d) Butan-2-one
Answer: b) Formaldehyde
Explanation: Tollens' test is used to detect aldehydes.
Formaldehyde (an aldehyde) will give a positive result, forming a silver mirror.
a) Propanal
b) Acetone
c) Butanoic acid
d) Ethanal
Answer: b) Acetone
Explanation: Acetone is a ketone, which contains the functional
group -CO- (carbonyl group) between two alkyl groups.
a) Methanal
b) Ethanal
c) Acetaldehyde
d) Formaldehyde
Answer: b) Ethanal
Explanation: CH3CHO is known as ethanal (or acetaldehyde), with
the functional group -CHO attached to an ethyl group.
a) Ethanoic acid
b) Acetaldehyde
c) Ethyl acetate
d) Methanol
Answer: b) Acetaldehyde
Explanation: The oxidation of ethanol (a primary alcohol)
produces acetaldehyde (an aldehyde) initially, which can be further oxidized to
acetic acid.
a) Ammoniacal silver nitrate
b) Bromine water
c) Sodium bisulfite
d) NaOH
Answer: a) Ammoniacal silver nitrate
Explanation: Ammoniacal silver nitrate (Tollens' reagent) is
used to distinguish aldehydes from ketones, as aldehydes reduce it to silver
metal, whereas ketones do not.
a) Formaldehyde
b) Acetone
c) Butan-2-one
d) Benzaldehyde
Answer: b) Acetone
Explanation: Acetone, being a ketone with an alpha-hydrogen,
can undergo aldol condensation when treated with a base.
a) A carboxylate salt
b) An alcohol
c) An addition compound
d) An ester
Answer: c) An addition compound
Explanation: The reaction of aldehydes with sodium bisulfite
(NaHSO3) results in the formation of an addition compound.
a) Reaction with sodium bisulfite
b) Reaction with alcohol
c) Reaction with ammonia or primary amine
d) Reduction by NaBH4
Answer: c) Reaction with ammonia or primary amine
Explanation: Aldehydes and ketones react with ammonia or
primary amines to form imines, which are a type of condensation product.
a) Acetone
b) Benzaldehyde
c) Acetophenone
d) Toluene
Answer: b) Benzaldehyde
Explanation: Fehling's test is used to test for aldehydes.
Benzaldehyde, being an aldehyde, will give a positive result, forming a red
precipitate.
a) Acetaldehyde
b) Crotonaldehyde
c) Benzaldehyde
d) Formaldehyde
Answer: b) Crotonaldehyde
Explanation: Crotonaldehyde is an α,β-unsaturated aldehyde
because it has a double bond between the α and β carbons of the aldehyde group.
a) Ethanal
b) Formaldehyde
c) Acetone
d) Cyclohexanone
Answer: d) Cyclohexanone
Explanation: Cyclohexanone, a cyclic ketone, does not undergo
nucleophilic addition as readily as aldehydes and other ketones.
a) Acetic acid
b) Propanoic acid
c) Butanoic acid
d) Formic acid
Answer: a) Acetic acid
Explanation: The oxidation of acetone (a ketone) leads to the
formation of acetic acid (a carboxylic acid).
a) Alcohol
b) Carboxylic acid
c) Ketone
d) Ester
Answer: a) Alcohol
Explanation: Sodium borohydride (NaBH4) reduces aldehydes to
primary alcohols.
a) Methanoic acid
b) Acetic acid
c) Propanoic acid
d) Butanoic acid
Answer: b) Acetic acid
Explanation: CH3COOH is known as acetic acid, a carboxylic
acid.
a) Nucleophilic substitution
b) Electrophilic substitution
c) Reduction to alcohol
d) Formation of ester on reaction with alcohols
Answer: d) Formation of ester on reaction with alcohols
Explanation: Carboxylic acids react with alcohols to form
esters in a reaction known as esterification.
a) Formic acid
b) Acetic acid
c) Benzoic acid
d) Maleic acid
Answer: d) Maleic acid
Explanation: Maleic acid, an unsaturated dicarboxylic acid, can
form a cyclic anhydride when dehydrated.
a) Alcohol
b) Sodium hydroxide
c) Ammonia
d) Hydrogen gas
Answer: a) Alcohol
Explanation: Carboxylic acids react with alcohols in the
presence of an acid catalyst to form esters.
a) Formic acid
b) Acetic acid
c) Oxalic acid
d) Butyric acid
Answer: c) Oxalic acid
Explanation: Oxalic acid is a dicarboxylic acid as it contains
two carboxyl groups (-COOH).
a) -OH
b) -COOH
c) -CHO
d) -CO-
Answer: d) -CO-
Explanation: The functional group of ketones is -CO-, which
consists of a carbonyl group (C=O) bonded to two carbon atoms.
a) Hydrogen gas
b) Sodium borohydride
c) Lithium aluminum hydride
d) Both b and c
Answer: d) Both b and c
Explanation: Both sodium borohydride (NaBH4) and lithium
aluminum hydride (LiAlH4) are strong reducing agents used to reduce aldehydes to
primary alcohols.
a) Propanoic acid
b) Acetic acid
c) Butanoic acid
d) Ethanoic acid
Answer: a) Propanoic acid
Explanation: CH3CH2COOH is propanoic acid, containing a
three-carbon chain with a carboxyl group.
a) A bisulfite addition product
b) An ester
c) A carboxylic acid
d) A ketone
Answer: a) A bisulfite addition product
Explanation: When benzaldehyde reacts with sodium bisulfite, it
forms a bisulfite addition product.
a) Reduction of aldehydes
b) Oxidation of alcohols
c) Dehydration of alcohols
d) Friedel-Crafts acylation
Answer: d) Friedel-Crafts acylation
Explanation: Friedel-Crafts acylation is a method used to
prepare ketones by reacting an aromatic compound with an acyl chloride in the
presence of a Lewis acid.
a) They are non-polar
b) They are highly soluble in water due to hydrogen bonding
c) They do not undergo esterification
d) They do not participate in electrophilic substitution
Answer: b) They are highly soluble in water due to hydrogen
bonding
Explanation: Carboxylic acids are polar and form hydrogen bonds
with water, making them highly soluble in water.
a) Alcohol
b) Carboxylic acid
c) Ketone
d) Ester
Answer: b) Carboxylic acid
Explanation: Acidified potassium dichromate is a strong
oxidizing agent and can oxidize aldehydes to carboxylic acids.
a) Acetate salt
b) Acetaldehyde
c) Acetone
d) Ethanol
Answer: a) Acetate salt
Explanation: When acetic acid reacts with sodium hydroxide, it
forms sodium acetate (acetate salt) and water.
a) Nucleophilic substitution
b) Nucleophilic addition
c) Electrophilic substitution
d) Free radical substitution
Answer: b) Nucleophilic addition
Explanation: Aldehydes and ketones undergo nucleophilic
addition reactions due to the electrophilic nature of the carbonyl carbon.
a) Carboxylic acid
b) Alcohol
c) Ester
d) Aldehyde
Answer: b) Alcohol
Explanation: Reduction of a ketone leads to the formation of a
secondary alcohol.
a) Acetate ester
b) Ethanoic anhydride
c) Acetone
d) Acetaldehyde
Answer: a) Acetate ester
Explanation: In the presence of sulfuric acid, acetic acid
reacts with ethanol to form ethyl acetate (acetate ester) in an esterification
reaction.
a) Tertiary alcohol
b) An addition compound
c) Ketone
d) Carboxylic acid
Answer: b) An addition compound
Explanation: Formaldehyde reacts with sodium bisulfite to form
an addition compound.
a) Propanoic acid
b) Butanoic acid
c) Acetic acid
d) Formic acid
Answer: a) Propanoic acid
Explanation: CH3CH2COOH is known as propanoic acid, a
three-carbon carboxylic acid.
a) Methanal
b) Ethanal
c) Propanal
d) Butanal
Answer: a) Methanal
Explanation: Methanal is commonly known as formaldehyde, which
is a simple aldehyde with the structure HCHO.
a) Acetone
b) Acetic acid
c) Benzophenone
d) Phenol
Answer: a) Acetone
Explanation: Acetone, a ketone, will undergo nucleophilic
addition due to the electrophilic carbonyl carbon.
a) -COOH
b) -CHO
c) -OH
d) -CO-
Answer: a) -COOH
Explanation: Carboxylic acids contain the carboxyl group
(-COOH), which is responsible for their acidic properties.
a) Iodoform
b) Carboxylic acid
c) Alcohol
d) Ester
Answer: a) Iodoform
Explanation: The reaction of aldehydes with sodium hydroxide
and iodine results in the formation of iodoform (CHI3), which is a
characteristic test for aldehydes containing a methyl group attached to the
carbonyl carbon.
a) Nucleophilic substitution
b) Esterification
c) Aldol condensation
d) Reduction
Answer: b) Esterification
Explanation: Aldehydes react with alcohols to form esters
through the process of esterification.
a) Tertiary alcohol
b) Secondary alcohol
c) Primary alcohol
d) Aldehyde
Answer: c) Primary alcohol
Explanation: The reduction of aldehydes produces primary
alcohols.
a) A carbonyl group attached to a hydrogen
b) A carbonyl group attached to two carbon atoms
c) A hydroxyl group attached to a carbon
d) A carboxyl group attached to a carbon
Answer: b) A carbonyl group attached to two carbon atoms
Explanation: Ketones have a carbonyl group (C=O) attached to
two alkyl groups or carbon atoms.
a) -OH
b) -CHO
c) -COOH
d) -CO-
Answer: c) -COOH
Explanation: The functional group of carboxylic acids is the
carboxyl group (-COOH).
a) Bromine water
b) Tollens' reagent
c) Sodium bicarbonate
d) Ferric chloride solution
Answer: b) Tollens' reagent
Explanation: Tollens' reagent is used to test for aldehydes,
forming a silver mirror in the presence of aldehydes.
a) Alcohol
b) Aldehyde
c) Ketone
d) Ester
Answer: a) Alcohol
Explanation: Carboxylic acids are reduced to alcohols upon
treatment with reducing agents like LiAlH4.
a) They have strong acidic properties
b) They undergo nucleophilic substitution
c) They contain a carbonyl group
d) They cannot form hydrogen bonds
Answer: c) They contain a carbonyl group
Explanation: Aldehydes and ketones both contain a carbonyl
group (C=O) which is the basis for their reactivity.
a) Formic acid
b) Acetic acid
c) Propanoic acid
d) Benzoic acid
Answer: c) Propanoic acid
Explanation: Primary alcohols can be oxidized to carboxylic
acids, and in the case of propanol, it will form propanoic acid.
a) Ethanal
b) Acetone
c) Benzene
d) Toluene
Answer: a) Ethanal
Explanation: Ethanal, being an aldehyde with α-hydrogens,
undergoes aldol condensation under basic conditions.
a) Acetone
b) Acetaldehyde
c) Propan-2-ol
d) Formaldehyde
Answer: d) Formaldehyde
Explanation: Formaldehyde, a simple aldehyde, does not exhibit
keto-enol tautomerism, whereas acetone and acetaldehyde do.
a) Oxidation of secondary alcohols
b) Oxidation of primary alcohols
c) Friedel-Crafts acylation
d) Dehydrogenation of aldehydes
Answer: a) Oxidation of secondary alcohols
Explanation: Ketones can be prepared by the oxidation of
secondary alcohols, where the hydroxyl group is oxidized to a carbonyl group.
a) Formic acid
b) Acetic acid
c) Propanoic acid
d) Butanoic acid
Answer: b) Acetic acid
Explanation: The oxidation of acetaldehyde (ethanal) produces
acetic acid (ethanoic acid).
a) NaBH4
b) DIBAL-H
c) Cr2O7^2-
d) H2O2
Answer: c) Cr2O7^2-
Explanation: Chromic acid (Cr2O7^2-) is used to oxidize primary
alcohols to aldehydes.
a) Formaldehyde
b) Acetaldehyde
c) Benzaldehyde
d) Propionaldehyde
Answer: a) Formaldehyde
Explanation: Formaldehyde (CH2O) has the simplest structure
among aldehydes, consisting of a single carbon atom bonded to a formyl group
(-CHO).