Only One Option Correct Type
Direction (Q. Nos. 1-26) This section contains 26 multiple choice questions. Each question has four choices (a), (6), (c) and (d), out of which ONLY ONE option is correct.
Which of the following statements is not generally true?
Fischer esterification is acid catalysed not base catalysed.
An equimolar mixture of benzoic acid and benzyl alcohol is dissolved in equal volumes of ether and 5% aqueous NaOH. The resulting mixture separates into two immiscible liquid layers. Which of the following is approximately correct?
Benzyl alcohol is not neutralised by NaOH, whereas benzoic acid forms salt C6H5COONa and goes into aqueous layer.
Fischer esterification of phenyl acetic acid with 1 -propanol gave a mixture of 93% of the ester, propyl phenylacetate, contaminated with 7% unreacted acid. Which of the following treatments would be best used to purify the ester?
Na2CO3 solution will neutralise unreacted PhCH2COOH and extract it into aqueous layer leaving ester is ether layer.
Which of the following would not be a useful reaction for preparing isobutyric acid, (CH3)2CHCO2H?
Two C8H9Br isomers form Grignard reagents which on carboxylation give isomeric carboxylic acids. Oxidation of each isomeric acid with hot KMnO4 produces the same C9H6O6 tricarboxylic acid. Which of the following compounds are the original isomeric bromides?
Both I and IV give the same
Which sequence of reactions would be best for the conversion of toluene into para-bromophenyiacetic acid? (NBS = N-bromosuccinimide)
Which of the following reagents are suitable for reducing an acyl chloride to an aldehyde?
I. LiAIH4 in ether
II. NaBH4 in fert-butanol
III. LiAIH(t - C4H9O)3 in ether at - 78°C
IV. H2 and Pd / BaSO4 catalyst
Both III and IV bring about controlled reduction of acid chloride into aldehyde.
What is the expected product from the double reaction drawn below?
Which of the following reactions is most likely to produce ethyl propanoate?
If diethyl amine is treated separately with the following derivatives of isobutyric acid, what order of reactivity is expected?
I. Isobutyronitrile (2-methylpropanenitrile)
II. Isobutyryl chloride (2-methylpropanoyl chloride)
III. Ethyl isobutyrate
IV. Isobutyric anhydride (2-methylpropanoic anhydride)
The order of reactivity of acid derivatives tow a rds nucle ophilic acyl substitution is
Acid chloride > Anhydride > Ester > Nitrile
The C—NH2 bond in acetamide is shorter than the C—NH2, bond in ethylamine. Why?
Pi bonding decreases the bond length of N—C bond.
Methyl esters of carboxylic acids, RCO2CH3, have somewhat higher molecular masses than 1°-amide, RCONH2, derivatives of the same acid. However, the amides have much higher boiling points. What is responsible for this difference?
Amide is capable of intermolecular H -bonding but ester does not.
Ethyl acetate undergoes the follow ing sequence of reactions,
I. treatment with excess phenylmagnesium bromide in ether
II. heating with Cone. H3PO4
III. treatment B2H6 in ether, followed by alkaline H2O2
IV. treatment with Jones’ reagent (CrO3 in aqueous acid + acetone)
Which of the following is the expected product? Note that C6H5 = phenyl
Which reactions would best accomplish in the following transformation ?
Adipic acid (hexanedioic acid) is converted to its diacid chloride by reaction with SOCI2, and this then reacts with 2 equivalents of sodium azide in ether solution. Addition of cone. HCl, followed by heating, results in considerable gas evolution and the formation of a crystalline water soluble solid. What is this product? (addition of aq. NaOH to the solid produces a foul smelling liquid.)
2, 2-dimethyl-1 , 3-cyclohexanedione is refluxed several hours in an aqueous dioxane solution of sodium hydroxide (10%). The resulting solution is adjusted to pH = 5 by the addition of dilute HCl and then extracted with ether. What compound has been prepared by this procedure?
Which set of reaction conditions is best suited for the preparation of 5-oxo-hexanoic acid from 5-bromo-2-pentanone?
A C7H9N base reacts with sodium nitrite and hydrochloric acid at 0°C, giving a clear solution. On heating with KCN and Cu2(CN)2 a gas evolves, and continued heating with conc. HCl yields a C8H8O4 crystalline acid. Heating this acid with aqueous KMnO4 produces a C8H6O4 product, which dehydrates on strong heating to give a crystalline C8H4O3 com pound. What is the C7H9N base?
Which of the following acids does not decarboxylate on heating?
It form s cyclic anhydride on heating.
What is the major product of the following reaction?
More stable acid derivative ester, not anhydride is formed.
Treatment of chiral ester I with one equivalent of LDA followed by allyl bromide II affords the alkylation product III.
Which of the following statement is true?
Planar α-carbon attack at the α-carbon of bromide to give racemic product.
What is the most likely product in the following reaction ?
The more stable amide is preferred over ester.
Arrange the following esters in the increasing order of reactivity towards base catalysed hydrolysis reaction.
If acid part is same, leaving group ability of alkoxide determines the reactivity.
The compound given below can be acetylated in a similar manner to acetylation of hydroxy benzoic acid to give salicylate ester derivatives. Which of the following product would result upon acetylation of this compound with acetic anhydride ?
The phenolic —OH group is most easily acetylated to give ester.
A C5H13N compound gives a base soluble derivative in the Hinsberg’s test. Which of the following best satisfy this condition?
Primary amine reacts with tosyl chloride to give sulphonamide which dissolve in KOH
Which of the following reagent cannot be used for differentiating propanamine from N-methyl butanamine?
Acid reacts with primary as well as secondary amine to form amide in the same manner.
Direction (Q. Nos. 27-30) This section is based on Statement I and Statement II. Select the correct answer from the codes given below.
Statement I : Consider the following neutralisation reaction,
Statement II : — SO3H is an electron withdrawing group, increases the acidity of — COOH.
—SO3H is more acidic than —COOH, hence sulphonic acid group would be neutralised first.
Statement I : If one mole of the following compound is treated with one mole of NaOH, one mole of phenyl propanoate is formed.
Statement II : Phenoxide ion (C6H5O-)has resonance stability.
Methyl propanoate would be formed because phenoxide is better leaving group than methoxide.
Statement I : Acetyl chloride (CH3COCI) undergoes faster nucleophilic substitution reaction (SN2) than chloroethane.
Statement II : In acetyl chloride, the leaving group (—Cl) is in resonance with the carbonyl
Both are correct but greater reactivity of acid chloride is due to sp2-hybridised carboxyl carbon and greater electrophilic character of the same.
Statement I : Ethyl acetoacetate (CH3COCH2COOC2H5) is very sparingly soluble in pure water and highly soluble in aqueous KOH solution.
Statement II : It’s methylenic (—CH2—) hydrogen is sufficiently acidic, forms salt with KOH quantitatively.
Formation of above salt is responsible for solubility.