Active Methylene Compounds MCQs [Organic Chemistry]

By: Prof. Dr. Fazal Rehman | Last updated: February 3, 2024

MCQs-based questions and answers on Active Methylene Compounds in organic chemistry.

Malonic ester can be used to prepare which of the following?

1. Carboxylic acids
2. Amino acids
3. Keto acids
4. All A, B, and C

Question’s Answer: All A, B, and C

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What is the order of percentage enolic character of malonic ester (I), acetoacetic ester (II) and cyanoacetic ester (III)?

1. II>I>II
2. III>II>1
3. I>II>III
4. II>III>I

Question’s Answer: II>III>I

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For preparation of various monocarboxylic acids malonic ester hydrolysis is treated with which of the following?

1. NaO C₂H₅
2. Na/C₂H₅OH
3. NaO C₂H₅
4. RX

Question’s Answer: NaO C₂H₅

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____is formed when Malonic ester reacts with urea in presence of POCI?

1. Parabamic acid
2. Barbituric acid
3. Veronal
4. Luminal

Question’s Answer: Barbituric acid

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In its synthetic applications cyanoacetic ester closely resembles

1. Ethyl acetoacetate
2. Acetoacetic ester
3. Nitroacetic ester
4. Malonic ester

Question’s Answer: Malonic ester

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The compound with which cyanoacetic ester can react but malonic ester cannot is

1. Acetone
2. Acetaldehyde
3. Acid halide
4. Alkyl halide

Question’s Answer: Acetone

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The reaction used for the preparation of ethyl acetoacetate starting from ethyl acetate is known as

1. Cannizzaro reaction
2. Claisen condensation
3. Michael condensation
4. Clasien-Schmidt reaction

Question’s Answer: Claisen condensation

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The enolic form of acetonacetic ester as compared to ketonic form contains ____.

1. One extra lone pair
2. One extra double bond
3. One less double bond
4. Both have same number of σ, л bonds and lone pairs

Question’s Answer: Both have same number of σ, л bonds and lone pairs

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Why Keto-enol tautomerism arises?

1. Due to Migration of enolic group
2. Due to Migration of a keto group
3. Due to Migration of a proton
4. Due to Migration of hydroxyl group

Question’s Answer: Due to Migration of a proton

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Which is true regarding Tautomers?

1. Tautomers must have Dynamic equilibrium between functional isomers
2. Tautomers must have Same functional group
3. Tautomers must have Same position of double bond
4. Tautomers must have Static equilibrium between functional

Question’s Answer: Tautomers must have Dynamic equilibrium between functional isomers

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What is the order of enolic contents of CH₃COCH₂COOC₂H₅(I), CH₃COCH₂COCH₃(II) and CH₃COCH₃CHO(III)?

1. I > II > III
2. I > III > II
3. III > II > I
4. II > III > I

Question’s Answer: II > III > I

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___________is not a reaction of enolic form of acetoacetic ester.

1. Coloration with FeCl₃
2. Addition of bromine
3. Acetylation
4. Reaction with HCN

Question’s Answer: Reaction with HCN

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Ethyl acetoacetate when boiled with aqueous KOH undergoes hydrolysis to form mainly ________ .

1. CH₃COCH₂ COOH
2. CH₃COOH
3. CH₃ CO CH₃
4. CH₃COCOOH

Question’s Answer: CH₃ CO CH₃

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Which is form after Reaction of ethyl acetoacetate with phenyl hydrazine?

1. Methyl isoxazolone
2. Methyl isoxapyrazolone
3. 3-Methyl-1-phenylpyrazolone
4. Dimethyl phenyl oxazolone

Question’s Answer: 3-Methyl-1-phenylpyrazolone

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Ethyl acetoacetate may be used to prepare

1. Ketonic acids
2. Ketones
3. Carboxylic acids
4. All A, B, and C

Question’s Answer: All A, B, and C

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Which of the following can be formed by Reaction of sodium ethoxide with malonic ester?

1. Resonance stabilized free radical
2. Resonance stabilized cation
3. Resonance stabilized anion
4. Resonance stabilized electrophile

Question’s Answer: Resonance stabilized anion

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Succinic acid may be obtained from sodiumalonic ester by its reaction with ______ by hydrolysis.

1. R-X
2. Dil.HCl
3. Alc.KOH
4. I₂

Question’s Answer: I₂

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A reactive methylene group is a methylene group present between what kind of groups.

1. Electron donating groups
2. Carbonyl groups
3. Hydroxyl groups
4. Amino groups

Question’s Answer: Carbonyl groups

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Which is not a reactive methylene compound?

1. CH₃CO CH₂COOC₂H₅
2. C₂H₅OOCCH₂CH₂CN
3. C₂H₅00CCH₂COOC₂H₅
4. C₂H₅OOCCH₂CH₂NH₂

Question’s Answer: C₂H₅OOCCH₂CH₂NH₂

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Which is the compound which exhibits keto-enol tautomerism?

1. C₂H₅O OC CH₂COCH
2. C₂H₅O OCCH₂NO₂
3. C₂H₅OOCCH₂CN
4. C₂H₅O OC CH₂CN

Question’s Answer: C₂H₅O OC CH₂COCH

More Organic chemistry MCQs

1. Organic chemistry MCQs
2. Active Methylene Compounds MCQs
3. Alcohols and Phenols MCQs
4. Carbonyl Compounds MCQs
5. Halogenated Organic Compounds MCQs
6. Carboxylic Acids MCQs
7. Hydrocarbons MCQs
8. Nitrogen-Containing Organic Compounds MCQs
9. Polymers MCQs
10. Nomenclature of Organic Compounds MCQs
11. Organic Acids and Bases MCQs
12. Organic Spectroscopy MCQs
13. Purification and Characterization of Organic Compounds MCQs
14. Reaction Mechanism MCQs
15. Stereochemistry MCQs
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