Aldehydes & Ketones PYQs Set 4 (PDF)

Set 4 of 9 · Questions 91-120 of 264

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Mere Teacher · Previous Year Questions NEET Chemistry · Aldehydes & Ketones · Set 4 (Q91-120)
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91. $What is the number of different products formed when mixture of ethanal and propanal reacts with aq. NaOH after warming?$ (1) $1$ (2) $3$ (3) $2$ (4) $4$ 92. $The reagent used in Wolff-Kishner reduction is$ (1) $NH_{2} - NH_{2} and KOH in ethylene glycol$ (2) $Zn - Hg / conc. HCl$ (3) $NaBH_{4}$ (4) $Na - Hg / H_{2} O$ 93. $What are ' X' and ' Y' respectively in the following reaction sequence? C_{6} H_{5} CH_{3} \to X C_{6} H_{5} CO_{2} H \to Y C_{6} H_{5} CH_{2} OH$ (1) $X=PCC; Y= (i) B_{2} H_{6} (ii) H_{3} O^{+}$ (2) $X= (i) KMnO_{4} / OH^{-}; Y = NaBH_{4} (ii) H_{3} O^{+}$ (3) $X= (i) KMnO_{4} / OH^{-}, Δ; Y= (i) B_{2} H_{6} (ii) H3O+ (ii) H3O+$ (4) $X = PCC; Y = LAH$ 94. $Identify product (A) in the following reaction. [NEET 2023] Zn - Hg Conc . HCl (A) + 2 H_{2} O$ (1) (2) (3) (4) 95. $In the following reaction Carbonyl compound + MeOH HCl ⇌ acetal Rate of the reaction is the highest for :$ (1) $Acetone as substrate and methanol in excess.$ (2) $Propanal as substrate and methanol in stoichiometric amount.$ (3) $Propanalas substrate and methanol in excess.$ (4) $Acetone as substrate and methanol in stoichiometric amount.$ 96. $The major product of the following reaction is: NaB H_{4} EtOH$ (1) (2) (3) (4) 97. $The compound A, C_{8} H_{8} O_{2} reacts with acetophenone to form a single product via cross-Aldol condensation. The compound A on reaction with conc. NaOH forms a substituted benzyl alcohol as one of the two products. The compound A is:$ (1) $2-hydroxy acetophenone$ (2) $4-methyl benzoic acid$ (3) $4-methoxy benzaldehyde$ (4) $4-hydroxy benzaldehyde$ 98. $Arrange the following in the correct order of their reactivity towards nucleophilic addition reactions$ (1) $I > III > IV > II$ (2) $IV > II > I > III$ (3) $II > III > I > IV$ (4) $III > I > IV > II$ 99. $Which of the following compounds will give positive iodoform test?$ (1) $Isopropyl alcohol$ (2) $Propionaldehyde$ (3) $Ethylphenyl ketone$ (4) $Benzyl alcohol$ 100. $In the following reaction Aldehyde + Alcohol HCl Acetal Aldehyde Alcohol HCHO tBuOH C H_{3} CHO MeOH The best combination is :$ (1) $C H_{3} CHO and^{t} BuOH$ (2) $HCHO and MeOH$ (3) $C H_{3} CHO and MeOH$ (4) $HCHO and^{t} BuOH$ 101. $A compound gives a positive test with I_{2} / NaOH and is extracted from benzene by saturated NaHSO_{3} . The compound is$ (1) $CH_{3} (CH_{2})_{4} CHO$ (2) $CH_{3} (CH_{2})_{3} COCH_{3}$ (3) $CH_{3} CH_{2} COCH_{2} CH_{3}$ (4) $CH_{3} (CH_{2})_{4} CH_{2} OH$ 102. $Nucleophilic addition reaction will be most favoured in$ (1) $C H_{3} C H O$ (2) $C H_{3} - C H_{2} - C H_{2} - C (= O) - C H_{3}$ (3) $(C H_{3})_{2} C = O$ (4) $C H_{3} C H_{2} C H O$ 103. $The oxidation of toluene to benzaldehyde by chromyl chloride is called$ (1) $Etard reaction$ (2) $Riemer‐Tiemann reaction$ (3) $Wurtz reaction$ (4) $Cannizzaro’s reaction.$ 104. $Identify compound X in the following sequence of reactions. [NEET 2020]$ (1) (2) (3) (4) 105. $Identify X, Y and Z in the following reactions sequence C_{6} H_{5} CH_{2} CH_{2} OH \to X C_{6} H_{5} CH_{2} COOH \to Y Z$ (1) $X = PCCY = NaOH, CaOZ = C_{6} H_{5} CH_{3}$ (2) $X = PCCY = LAH Z = C_{6} H_{5} CH_{2} CH_{3}$ (3) $X = Jones reagent Y = NaOH, CaO Z = C_{6} H_{5} CH_{2} CH_{3}$ (4) $X = Jones reagent Y = NaOH, CaO, Δ Z = C_{6} H_{5} CH_{3}$ 106. $Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as [NEET 2020]$ (1) $Cannizzaro's reaction$ (2) $Cross Cannizzaro's reaction$ (3) $Cross aldol condensation$ (4) $Aldol condensation$ 107. $Assertion A: Enol form of acetone (CH_{3} COCH_{3}) exists in < 0.1 % quantity. However, the enol form of acetyl acetone (CH_{3} COCH_{2} OCCH_{3}) exists in approximately 15 % quantity. Reason R : enol form of acetyl acetone is stabilized by intramolecular hydrogen bonding, which is not possible in enol form of acetone. Choose the correct statement:$ (1) $A is false but R is true$ (2) $Both A and R are true and R is the correct explanation of A$ (3) $Both A and R are true but R is not the correct explanation of A$ (4) $A is true but R is false$ 108. $Match List - I with List - II. List - I Reagents (A) H_{2}, Pd - BaSO_{4} (B) SnCl_{2}, HC l (C) CrO_{2} Cl_{2}, CS_{2} (D) CO, HCl, Anhyd. AlCl_{3} List - II Reaction Name (Involving aldehydes) (I) Etard Reaction (II) Rosenmund Reduction (III) Gatterman - Koch Reaction (IV) Stephen Reaction Choose the correct answer from the options given below :$ (1) $A-IV, B-III, C-I, D-II$ (2) $A-II, B-IV, C-I, D-III$ (3) $A-IV, B-I, C-II, D-III$ (4) $A-II, B-III, C-IV, D-I$ 109. $Which of the following sets is in the correct order regarding the property mentioned against them? Sets Property I. NCCH_{2} COOH > FCH_{2} COOH Acidity > H_{3} CCH_{2} COOH II. CH_{3} CH_{2} CHO > PhCOCH_{3} > PhCHO Reactivity III. H_{3} COCH_{2} CH_{3} < H_{3} CCH_{2} CHO < H_{3} CCH_{2} CH_{2} OH Boiling points$ (1) $I, II only$ (2) $I, III only$ (3) $II, III only$ (4) $I, II. III$ 110. $Which of the following is a hemiacetal?$ (1) (2) (3) (4) 111. $Fchling's solution " A" is [NEET 2024]$ (1) $aqueous copper sulphate$ (2) $alkaline copper sulphate$ (3) $alkaline solution of sodium potassium tartrate (rochelle's salt)$ (4) $aqueous sodium citrate$ 112. $The major product of the following reaction is: C H_{3} C H_{2} - P h C O H - C H_{3} cannot be prepared by :$ (1) $C H_{3} C H_{2} C O C H_{3} + P h M g X$ (2) $P h C O C H_{2} C H_{3} + P h M g X$ (3) $P h C O C H_{3} + C H_{3} C H_{2} M g X$ (4) $H C H O + P h C H (C H_{3}) C H_{2} M g X$ 113. $Aldehydes or ketones when treated with C_{6} H_{5} - NH - N H_{2}, the product formed is$ (1) $semicarbazone$ (2) $phenylhydrazone$ (3) $hydrazine$ (4) $oxime$ 114. $Acetaldehyde reacts with$ (1) $electrophiles only$ (2) $nucleophiles only$ (3) $free radicals only$ (4) $both electrophiles and nucleophiles.$ 115. $Trichloroacetaldehyde was subjected to Cannizzaro's reaction by using NaOH. The mixture of the products contains sodium trichloroacetate ion and another compound. The other compound is$ (1) $2, 2, 2-Trichloroethanol$ (2) $Trichloromethanol$ (3) $2, 2, 2-Trichloropropanol$ (4) $Chloroform$ 116. $What type of reaction is the formation of aldol from aldehyde?$ (1) $Condensation reaction$ (2) $Addition reaction$ (3) $Substitution reaction$ (4) $Elimination reaction$ 117. $Which of the following is incorrect?$ (1) $F e C 1_{3} is used in detection of phenol.$ (2) $Fehling solution is used in detection of glucose.$ (3) $Tollens’ reagent is used in detection of unsaturation.$ (4) $N a H S O_{3} is used in detection of carbonyl compound.$ 118. (1) (2) (3) (4) 119. $Bouveault-Blanc reduction reaction involves:$ (1) $Reduction of an anhydride with L i A l H_{4} .$ (2) $Reduction of an ester with Na/ C_{2} H_{5} OH.$ (3) $Reduction of a carbonyl compound with Na/Hg and HCl.$ (4) $Reduction of an acyl halide with H_{2} /Pd$ 120. $A in the above reaction is :$ (1) (2) (3) (4)