Choose correct answer-
(a) Both assertion and reason are correct statements, and reason is the correct explanation of the assertion.
(b) Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion.
(c) Assertion is correct, but reason is wrong statement.
(d) Assertion is wrong, but reason is correct statement.
HALOGEN COMPOUNDS
1. Assertion: Iodoalkanes undergo nucleophilic substitution more readily than bromoalkenes.
Reason: Iodine is a better leaving group due to its larger size which makes the covalent bond weaker.
Ans- a
2. Assertion: SN2 mechanism leads to racemisation.
Reason: The incoming nucleophile attacks the compounds from the side opposite to the outgoing nucleophle in SN2 mechanism.
Ans- d
3. Assertion: Haloalkanes react with KCN to form cyanoalkanes.
Reason: KCN completely ionises in solution.
Ans- a
4. Assertion: Chlorobenzene is less polar than chloro methane.
Reason: Chlorobenzene has a longer C-Cl bond due to resonance.
Ans- c
5. Assertion: Presence of nitro group at ortho or para position makes nucleophilic substitution in chlorobenzene easier.
Reason: Nitro group donates electrons to stabilize the intermediate ion formed by the addition of the incoming nucleophile.
Ans- c
6. Assertion: Chloroform must be stored in dark coloured bottles.
Reason: Chloroform reacts with air to form phosgene.
Ans- b
7. Assertion: Chlorobutane has lower boiling point than 2-Chloro-2-methylpropane.
Reason: The intermolecular forces in straight chain compounds are stronger than in branched compounds.
Ans- a
8. Assertion: Benzyl chloride undergoes nucleophilic substitution through SN1 mechanism.
Reason: Benzyl carbocation is resonance stabilized.
Ans- a
9. Assertion: Haloalkanes are only sparingly soluble in water.
Reason: Haloalkanes cannot form hydrogen bonds with water molecules.
Ans- b
10. Assertion: Propene reacts with HBr to form 2-bromopropane.
Reason: The intermediate carbocation formed will be secondary since it is more stable than primary.
Ans- a
ALCOHOLS, PHENOLS AND ETHERS
1. Assertion: Phenols are more acidic than aliphatic
alcohols.
Reason: The phenoxide ion is more resonance stabilised than alkoxide ion.
Ans- a
2.Assertion: Tertiary alcohols gets converted into an alkene instead of a carbonyl Compounds in the presence of heated metallic copper.
Reason: Tertiary alcohols prefer to undergo dehydrogenation instead of dehydration in the presence of heated copper.
Ans-c
3.Assertion: Ethers are non-polar when they are symmetrical.
Reason: Ethers have a bent structure.
Ans- d
4.Assertion: n-Butanol has higher boiling point than 2-methyl propan-2-ol.
Reason: Branching increases the strength of vander-waals forces.
Ans- c
5. Assertion: It is not possible to prepare anisole from chlorobenzene through willamson’s synthesis.
Reason: The C-Cl bond in chlorobenzene shows partial double bond character due to resonance.
Ans- a
6.Assertion: Nitro phenol has lower pKa value than phenol.
Reason: The electron withdrawing nature of the nitro group further stabilises the phenoxide ion formed.
Ans- a
7.Assertion: Anisole reacts with HI to give phenol and chloromethane.
Reason: The –OCH3 group in anisole enriches the electron density in the ring through resonance.
Ans- b
8.Assertion: It is not possible to purify alcohol beyond 95% purity by simple distillation.
Reason: The intermolecular hydrogen bond in alcohol increases the boiling point of 95% alcohol.
Ans- c
9.Assertion: Ethanol can be distinguished from methanol using iodoform test.
Reason: Ethanol has a methyl group attached to a carbon containing hydroxyl groups.
Ans- a
10.Assertion: Methanol is called wood spirit.
Reason: Methanol can be prepared by the destructive distillation of fresh wood.
Ans- a
ALDEHYDES, KETONES AND ACIDS
1.Assertion: Carboxylic acids do not show properties of carbonyl group.
Reason: The -C=O in carboxyl group is in resonance with the -OH group.
Ans-a
2.Assertion: Chloro acetic acid has higher pKa value than Acetic acid..
Reason: The – I effect of Cl further stabilises the carboxylate anion formed by the loss of the proton.
Ans-d
3.Assertion: Benzaldehyde resists nucleophilic addition in comparison with Ethanal
Reason: The Phenyl group in benzaldehyde is too bulky and therefore prevents attack of Nucleophile.
Ans- c
4.Assertion: Aldehydes undergo aldol condensation only if it has α-hydrogen.
Reason: The α-hydrogen in aldehydes are acidic in nature because the anion formed by the loss of the α-hydrogen is resonance stabilized.
Ans-a
5.Assertion: Ketones have low boiling point compared to corresponding alcohols.
Reason: Ketones from intermolecular hydrogen bonding with alcohols.
Ans- b
6.Assertion: Carboxylic acids have greater boiling point than alcohols.
Reason: Carboxylic acids have the ability to form dimers in solution.
Ans- b
7.Assertion: Dry HCl is a must for reaction of aldehyde with alcohol to form hemiacetal.
Reason: HCl protonates the carbonyl oxygen increasing the electrophilicity of the carbonyl carbon.
Ans- a
8.Assertion: Even though there are two NH2 groups in semicarbazide, only one reacts with carbonyl compounds
Reason: Semicarbazide has two NH2 groups out of which one is in resonance with the carbonyl group.
Ans-a
9.Assertion: Benzoic acid does not undergo Freidel Crafts reaction.
Reason: The carboxyl group in benzoic acid donates electrons into the ring through resonance.
Ans-c
10.Assertion: Ketones are more reactive thatn aldehydes towards nucleophilic addition.
Reason: The alkyl groups in ketone increases the electron density on the carbonyl carbon through +I effect.
Ans-d
AMINES
1.Assertion: Hoffmann’s ammonolysis can be used to prepare pure primary amines.
Reason: Ammonolysis of haloalkanes lead to multiple substitution of alkyl groups on nitrogen.
Ans- d
2.Assertion: Aniline is less basic than ammonia.
Reason: The lone pair on nitrogen in aniline is donated
into the ring through resonance.
Ans-a
3.Assertion: Tertiary amines have lower boiling point
than corresponding secondary and
primary amines.
Reason: Tertiary amines have higher intermolecular hydrogen bonding.
Ans-c
4.Assertion: Tertiary amines do not undergo acylation reaction.
Reason: There are no replaceable hydrogens on the nitrogen in tertiary amines.
Ans-a
5.Assertion. Carbyl amine reaction cannot be used as a test to distinguish between aniline and methanamine.
Reason: Both aniline and methanamine are primary amines.
Ans-a
6.Assertion: Diazotisation of aniline should be done near 0oC.
Reason: Aniline is less reactive towards sodium nitrite at normal temperatures.
Ans-c
7.Assertion: Aniline forms significant amount of meta derivative on nitration with con.HNO3 and Conc. H2SO4
Reason: The ortho and para positions in aniline is electron rich due to the activating nature of -NH2 group.
Ans- b
8.Assertion: Aniline does not undergo Freidel Crafts reaction.
Reason: Being a Lewis base, aniline reacts with anh.AlCl3 to form salt.
Ans- a
9.Assertion: Aniline cannot be prepared by Gabriel
phthalimide synthesis.
Reason: Phthalimide does not react with chlorobenzene
due to large size of phenyl group.
Ans- c
10.Assertion: Acetylation of aniline enhances the tendency to undergo electrophilic substitution.
Reason: Acetylation reduces the activation of the benzene ring by the NH2 group since it can undergo resonance with both benzene ring and Acetyl group.
Ans- d
BIOMOLECULES
1.Assertion: The hydrolysis of sucrose to glucose and
fructose is called inversion of cane sugar.
Reason: The dextro rotatory sucrose forms a laevo rotatory mixture on hydrolysis.
Ans- a
2.Assertion: Glycine is not optically active.
Reason: There is no asymmetrical carbon in glycine to make it chiral.
Ans- a
3.Assertion: Vitamin C has to be continuously supplied through diet.
Reason: Vitamin C is a water soluble vitamin.
Ans- a
4.Assertion: Amino acids in a protein remain intact even when it is denatured.
Reason: The primary structure of protein is broken to give individual amino acids on denaturation.
Ans-c
5.Assertion. Despite having aldehyde group, aldehyde does not show Schiff’s test.
Reason: The aldehyde group in glucose is used to from the ring structure of glucose.
Ans- a
6.Assertion: Non-essential amino acids are not necessary for protein synthesis.
Reason: Non-essential amino acids are produced in the human body.
Ans- d
7.Assertion: Naturally occurring amino acids have
L-configuration.
Reason: The structure of naturally occurring amino
acids have similarity with L-glyceraldehyde.
Ans-b
8.Assertion: Increased level of glucagon will improve the
glucose content in blood.
Reason: Glucagon and insulin regulates the sugar levels in blood.
Ans- b
9.Assertion: Less intake of iodine in diet leads to enlargement of thyroid gland
Reason: iodine deficiency leads to hyperthyroidism.
Ans- c
10.Assertion: The bond between adenine and thymine is stronger than the bond between Cytosine and guanine.
Reason: Cytosine and guanine have a triple hydrogen bond while adenine and thymine have a double hydrogen bond.
Ans- d