CLASS
– XII (FOR M.P.BOARD)
ALDEHYDES,
KETONES AND
CARBOXYLIC
ACIDS
Objective Type Questions
Q. 1. Choose the correct option:
1. Cannizzaro reaction does not give
(a)
Formaldehyde (b) Acetaldehyde
(c)
Benzaldehyde (d) None of the
above.
2. The main product of Rosenmund's reaction is:
(a) Aldehyde (b) Ketone
(c)
Carboxylic acid (d) Ester
3. Which of the following gives silver mirror test:
(a) Aldehyde (b) Ketone (c) Alcohol (d) Alkyl
halide.
4. Which compound is obtained when calcium acetate
is heated
(a) Methanol
(b) Acetone
(c)
Acetaldehyde (d) Ethyl acetate.
5. Which of the following does not give pink colour
when treated with Schiff's reagent:
(a)
Formaldehyde (b) Benzaldehyde
(c) Acetone (d)
Acetaldehyde.
6. Which of
the following does not contain -OH group:
(a)
Carboxylic acid (b) Aldehyde
(c) Alcohol (d) Phenol.
7. Which of the following compound is obtained by
the oxidation of isopropyl alcohol :
(a) Acetone
(b) Ether
(c) Acetic
acid (d)
Acetaldehyde.
8. On oxidation, aldehyde forms:
(a) Acid (b) Ether (c) Ketone (d) Alcohol.
9. Compounds CH₂CH₂OCH₂CH, and CH₂OCH₂CH₂CH3 are:
(a)
Tautomers (b) Metamers
(c)
Functional isomers (d) Optical
isomers.
10. In which of the following the Cannizzaro reaction
takes place
(a) CH3COCH3 (b) C6H5CHO (c) CH3CHO (d) C₂H5OH.
11. On hydrolysis of acetamide, it gives
(a) Acetic acid (b) Acetaldehyde
(c) Methyl
amine (d) Formic acid.
12. Hydrolysis of base and ester is called:
(a)
Esterification (b)
Saponification
(c)
Alkalization (d) Dehydration.
13. The nature of diethyl ether is :
(a) Similar
to reducing agent (b) Similar to oxidizing agent
(c) Similar
to Lewis acid (d) Similar to Lewis base.
14. Which is prepared by dry distillation of
calcium acetate:
(a) Formaldehyde (b) Acetaldehyde
(c) Acetone (d) Acetic acid.
15. Acid contains in vinegar is:
(a)
Formaldehyde (b)
Acetaldehyde
(c) Acetone (d)
Acetic acid.
16. Which
of the reactions below can result in ketones?
a) Oxidation of primary alcohols
b) Oxidation of
secondary alcohols
c) Dehydrogenation of tertiary alcohols
d) Dehydrogenation of primary alcohols
17. The
Rosenmund reaction can produce which of the following carbonyl compounds?
a) Methanal b) Benzaldehyde
c) Butanone d)
Acetone
18.
Reactions occur between aldehydes and ketones.
a) nucleophilic
addition b)
electrophilic substitution
c) electrophilic addition d)
nucleophilic substitution
19. Which
of the following reactions to a nucleophilic assault is the least reactive?
a) Acetaldehyde b) Di Tert-Butyl ketone
c) Diisopropyl ketone d)
Butanone
20. Acetone
combines with ethylene glycol in dry HCl gas to generate _________
a) hemiacetals b) cyclic ketals
c) cyclic acetals d)
acetals
21. Which
of the following is not a formaldehyde application?
a) Preservation of biological specimens
b) Preparation
of acetic acid
c) Silvering of mirrors
d) Manufacturing of bakelite
22. Which
of the following compounds is formed when benzyl alcohol is oxidised with KMnO4?
a) CO2 and
H2O b)
Benzoic acid
c) Benzaldehyde d)
Benzophenone
23. Which
of the following substances is the least water-soluble?
a) Methanal b) Pentanal
c) Propanone d) Ethanal
24. Which
of these has the least unpleasant odour?
a) Methanal b) Butanal
c) Propanal d) Ethanal
Q. 2. Fill in the blanks :
1. Primary
alcohols are oxidised to form (Aldehydes)
2. On
reaction of formaldehyde with ammonia is obtained.
(Urotropine)
3. Ketones
are reduced to form.............. alcohols.
( Secondary)
4. Boiling
point of ketone is than isomeric aldehyde. (Higher)
5. Aldehyde
and ketone contains ..........group. (Carbonyl)
6…………………are
given by ketones on clemmensen reduction (Alkanes)
7. On
oxidation of primary alcohols fatty acids are obtained in which number of
carbon atoms is ………………………… (Same)
8. Tollen's
reagent is...........
[Ammoniacal silver nitrate (AgNO3)]
9...............
is obtained from red ants (Formic acid)
10. Those
aldehydes and ketones which contain give aldol condensation. (A-hydrogen atom)
Q. 3. Answer in one word / sentence:
1. A
solution of ammoniacal silver nitrate is called.
(Tollen reagent)
2. What is
the hybridised state of the primary carbon in aldehyde ?(sp2)
3. Name the
reaction that produces the corresponding aldehyde from acid chlorides. (Rosenmund reduction)
4. Aldol
condensation takes place in which type of aldehyde and ketone ?
(a-hydrogen containing aldehydes and ketones)
5. Primary
amine is obtained when hydrazoic acid is treated with fatty acids. This
reaction is called.
(Schmidt reaction)
6. The
reaction of formaldehyde with conc. NaOH. What is it called. (Cannizzaro reaction)
7. Which
give reddish brown precipitate with Fehling solution. (Aldehyde)
Short Answer Type Questions
Q. 1.
What is Formalin? Write its uses.
Ans.
Formalin: 40% aqueous solution of formal- dehyde
(HCHO) is
known as Formalin.
Uses: (i) In cleaning the rooms of
patients.
(ii) In the
preservation of dead bodies.
Q. 2.
Why ketones are less reactive than aldehydes ?
Ans.
Ketones are less reactive than aldehydes because in ketones there are two alkyl
groups attached with carbonyl group, due to the positive inductive effect (+I)
of both the alkyl groups, the positive charge on carbon atom decreases.
Hence, the
sensitivity of ketones to the nucleophilic reagents decreases.
In
aldehydes, they have only one alkyl group, so they are more reactive than
ketones.
Q.3 What is Tollen’s reagent? Write its reaction with
acetaldehyde.
Tollen’s Reagent:- Ammoniacal silver nitrate solution is known as Tollen’s reagent. When
Tollen’s reagent is heated with aldehyde, aldehyde reduces Ag+ to Ag
and forms a bright silver mirror on the wall.
Q.4 Explain Fehling reaction with equation.
Fehling Reaction:- Sodium, Potassium tartarate associated with alkaline
CuSO4 is known as Fehling solution. When aldehyde
is heated with Fehling solution, then aldehyde is oxidized and red precipitate
of cuprous oxide is obtained. This is known as Fehling test.
Q.5 Why is the boiling point of ketone little higher than its
corresponding isomeric aldehyde?
Ketones are comparatively more polar than their corresponding isomeric
alde – hyde because the >C=O group in ketone is linked with two electron
releasing alkyl group. Thus, the dipole attractive force of ketone is
comparatively higher. This is the reason that the boiling point of ketone is
comparatively higher than its corresponding isomeric aldehyde.
Q.6 Compare
acidic strength of acetic acid, formic acid and chloroacetic acid.
Chlorine
atom present in chloroacetic acid has strong negative inductive effect (-I).
Due to this, electrons of O – H bond easily displaced towards oxygen and it
releases H+ easily. CH3 group present in CH3COOH which produces (+I) effect causes decrease in
acidic nature.
In formic acid there is no such group which produces (+1) or
(-1) effect. Hence, formic acid is stronger than acetic acid and chloroacetic
acid is stronger than acetic acid.
In short chloroacetic acid is stronger than formic acid and
formic acid is stronger than acetic acid.
