Questions on Polymerization – Addition and Condensation Polymers (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions on Polymerization – Addition and Condensation Polymers (Organic Chemistry)

20 multiple-choice questions on Polymerization – Addition and Condensation Polymers (Organic Chemistry). Each question has five alternatives (A–E), and a complete answer key with extended explanations is provided at the end.

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Multiple Choice Questions: Polymerization (Addition and Condensation Polymers)

1. What is polymerization?

A) Breakdown of large molecules into smaller units

B) Process of combining monomers to form a polymer

C) Conversion of a liquid into gas

D) Removal of hydrogen atoms

E) Conversion of polymers into monomers

2. What type of monomer is required for addition polymerization?

A) Monomers with hydroxyl groups

B) Monomers with amine groups

C) Monomers with carbon-carbon multiple bonds

D) Monomers with carbonyl groups

E) Saturated hydrocarbons

3. Which of the following polymers is formed through addition polymerization?

A) Nylon

B) Polyester

C) Polyethene

D) Protein

E) Cellulose

4. What is the repeating unit in polyethene?

A) –CH=CH–

B) –CH₂–CH₂–

C) –CH₂–CHCl–

D) –C₆H₄–

E) –CO–NH–

5. Which of the following best describes condensation polymerization?

A) Monomers join by breaking double bonds

B) Monomers form polymers with no by-product

C) Monomers join with elimination of a small molecule

D) Requires UV light to initiate

E) Involves free radical chain reactions

6. What is a typical by-product of condensation polymerization?

A) CO₂

B) CH₄

C) H₂O

D) C₂H₂

E) NH₃

7. Which polymer is made by condensation polymerization?

A) Polypropene

B) Polystyrene

C) Nylon

D) Polyethene

E) PVC

8. What monomers are used to make nylon-6,6?

A) Dicarboxylic acid and diamine

B) Diol and diacid

C) Alkene and alcohol

D) Ketone and amine

E) Alkyne and ether

9. In addition polymerization, what initiates the reaction?

A) Oxygen

B) Water

C) Heat and acid

D) Free radicals

E) Ammonia

10. Which condition is necessary for free-radical polymerization?

A) Dehydration

B) Base catalysis

C) Presence of water

D) Radical initiator like benzoyl peroxide

E) Sunlight only

11. What distinguishes addition from condensation polymerization?

A) Addition requires elimination of a molecule

B) Addition polymerization requires monomers with two functional groups

C) Condensation polymerization produces no by-product

D) Condensation eliminates small molecules

E) Both only occur in gases

12. Which polymer is used to make plastic bottles and is made by condensation?

A) Polyethene

B) Nylon

C) PET (polyethylene terephthalate)

D) PVC

E) Polypropylene

13. What is the functional group in polyester?

A) –OH

B) –COOH

C) –C–O–C–

D) –COO–

E) –NH₂

14. What is the structural difference between polyethene and polystyrene?

A) Polyethene has chlorine atoms

B) Polystyrene has benzene rings as side groups

C) Polyethene is branched

D) Polystyrene is a copolymer

E) Polyethene is made by condensation

15. Which of the following is a biodegradable polymer?

A) PVC

B) Polyethene

C) Nylon

D) Polylactic acid (PLA)

E) Polystyrene

16. What is the main environmental concern with addition polymers?

A) They are acidic

B) They degrade too easily

C) They are explosive

D) They are non-biodegradable

E) They are soluble in water

17. What is a copolymer?

A) Polymer made from one type of monomer

B) Polymer made by condensation only

C) Polymer formed by mixing different polymers

D) Polymer made from two or more different monomers

E) Polymer with alternating single and triple bonds

18. Which of the following correctly matches polymer with its monomer?

A) Polyethene – ethyne

B) Nylon – amino acid

C) Polyester – ethene

D) Polypropene – propene

E) PVC – ethanoic acid

19. What is a key characteristic of monomers in condensation polymerization?

A) Must have double bonds

B) Must have at least two reactive functional groups

C) Must be gases

D) Must contain halogens

E) Must be cyclic compounds

20. What type of bond is formed during the formation of polyamides?

A) Ether

B) Ester

C) Amide

D) Alkene

E) Carbonate

Questions on Polymerization – Addition and Condensation Polymers (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. B – Polymerization joins monomers into polymers via chemical bonding.

2. C – Addition polymerization requires unsaturated monomers like alkenes.

3. C – Polyethene is formed from ethene by addition polymerization.

4. B – The repeating unit in polyethene is –CH₂–CH₂–.

5. C – Condensation involves elimination of a small molecule like water or methanol.

6. C – The most common by-product in condensation reactions is H₂O (water).

7. C – Nylon is made by condensation of diamine and dicarboxylic acid.

8. A – Hexanedioic acid and hexamethylenediamine form nylon-6,6.

9. D – Free radicals initiate addition polymerization in many cases.

10. D – Benzoyl peroxide is a free-radical initiator for polymerization.

11. D – Condensation polymerization eliminates small molecules like water or HCl.

12. C – PET is used in bottles and made by condensation polymerization.

13. D – Esters (–COO–) are the linkage in polyesters.

14. B – Polystyrene has phenyl groups as side chains.

15. D – PLA is a biodegradable polymer made from renewable sources.

16. D – Addition polymers like polyethene are not biodegradable, posing waste issues.

17. D – Copolymers are made from two or more different monomers.

18. D – Polypropene is made from propene via addition.

19. B – Condensation monomers must have two functional groups to form polymers.

20. C – Amide bonds link monomers in polyamides like nylon.

Questions on Condensation Reactions (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions on Condensation Reactions (Organic Chemistry)

20 multiple-choice questions on Condensation Reactions in Organic Chemistry, each with five answer choices (A–E). The correct answers with extended explanations are provided at the end.

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Multiple Choice Questions: Condensation Reactions (Organic Chemistry)

1. What characterizes a condensation reaction?

A) Addition of hydrogen across a double bond

B) Combination of molecules with the elimination of a small molecule

C) Substitution of a halogen for hydrogen

D) Breaking of carbon-carbon bonds

E) Rearrangement of atoms without bond changes

2. Which of the following small molecules is commonly eliminated in a condensation reaction?

A) CO₂

B) CH₄

C) H₂O

D) O₂

E) Cl₂

3. What is formed when a carboxylic acid reacts with an alcohol in a condensation reaction?

A) Amide

B) Ester

C) Ether

D) Aldehyde

E) Ketone

4. What type of condensation reaction occurs between two amino acids?

A) Alkylation

B) Esterification

C) Peptide bond formation

D) Halogenation

E) Hydrolysis

5. Which of the following best describes esterification?

A) Condensation reaction forming an ether

B) Substitution reaction of an alcohol with water

C) Condensation reaction between an alcohol and a carboxylic acid

D) Addition of water to a double bond

E) Elimination of hydrogen

6. Which catalyst is typically used in esterification reactions?

A) NaOH

B) HCl

C) H₂SO₄

D) KOH

E) NH₃

7. What is the main by-product of a typical esterification reaction?

A) Oxygen

B) Hydrogen

C) Water

D) Carbon monoxide

E) Hydroxide

8. What type of bond is formed during peptide bond formation?

A) C–C single bond

B) C–N amide bond

C) O–H bond

D) N–H bond

E) C=C double bond

9. What functional groups are involved in the formation of an amide via condensation?

A) Alcohol and ether

B) Amine and alcohol

C) Carboxylic acid and amine

D) Ketone and aldehyde

E) Alkene and acid

10. Which reaction type is the reverse of a condensation reaction?

A) Addition

B) Substitution

C) Oxidation

D) Hydrolysis

E) Polymerization

11. What distinguishes condensation polymerization from addition polymerization?

A) Only uses unsaturated monomers

B) No by-product formed

C) Small molecule like water is eliminated in condensation

D) Requires radicals

E) Occurs only with alkenes

12. Which of the following is a product of condensation polymerization?

A) Polyethene

B) Polyvinyl chloride

C) Polyester

D) Polystyrene

E) Polyisoprene

13. Which pair of monomers can form a polyester through condensation?

A) Dicarboxylic acid and diol

B) Alkene and alkyne

C) Alcohol and aldehyde

D) Amine and alkane

E) Ether and ketone

14. Which of the following is a necessary condition for condensation polymerization?

A) Presence of radicals

B) Elimination of water or other small molecule

C) UV light

D) Free electrons

E) Basic pH

15. What happens in a Claisen condensation?

A) Two esters react to form a β-keto ester

B) Alcohol reacts with carboxylic acid

C) Two alkenes join together

D) Halogen replaces hydroxyl group

E) Amine and aldehyde form amide

16. In biological systems, condensation reactions are important in:

A) Protein hydrolysis

B) Lipid breakdown

C) Formation of DNA and proteins

D) Combustion of glucose

E) Cell respiration

17. What functional group results from a condensation between a carboxylic acid and an amine?

A) Alcohol

B) Ketone

C) Ester

D) Amide

E) Ether

18. What is typically required for ester hydrolysis (reverse of condensation)?

A) Acid or base and water

B) Light and heat

C) Alcohol and oxidizer

D) Ammonia and heat

E) NaCl and acid

19. Which biological macromolecule is formed through condensation reactions?

A) Water

B) Lipids

C) Proteins

D) Oxygen

E) Monosaccharides

20. What is a common characteristic of condensation polymers?

A) Formed by radical addition

B) Contain only carbon and hydrogen

C) Include functional groups like ester or amide bonds

D) Do not involve elimination

E) Are always aromatic

Questions on Condensation Reactions (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. B – Condensation involves joining of two molecules with the elimination of a small molecule (e.g., H₂O).

2. C – Water is the most common molecule eliminated in condensation reactions.

3. B – A carboxylic acid and alcohol form an ester and water in esterification.

4. C – Amino acids link via peptide bonds through condensation.

5. C – Esterification is a condensation reaction between alcohol and acid.

6. C – Concentrated sulfuric acid (H₂SO₄) acts as a catalyst and dehydrating agent.

7. C – The by-product of esterification is water.

8. B – Peptide bonds are C–N amide bonds.

9. C – Amine + Carboxylic acid → Amide + Water in condensation.

10. D – Hydrolysis breaks down compounds formed by condensation.

11. C – Condensation polymerization eliminates small molecules like water.

12. C – Polyesters are formed by condensation (e.g., PET).

13. A – Diols and dicarboxylic acids form polyesters.

14. B – Condensation requires elimination of small molecules.

15. A – Claisen condensation: two esters → β-keto ester.

16. C – DNA, proteins, and polysaccharides are built by condensation reactions.

17. D – Carboxylic acid + Amine → Amide.

18. A – Hydrolysis of esters requires water + acid/base catalyst.

19. C – Proteins are formed by condensation of amino acids.

20. C – Condensation polymers often contain ester or amide functional groups.

Questions on Oxidation Reactions (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions on Oxidation Reactions (Organic Chemistry)

20 multiple-choice questions on Oxidation Reactions in Organic Chemistry, each with five answer choices (A–E). At the end, you’ll find a complete answer key with extended explanations.

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Multiple Choice Questions: Oxidation Reactions (Organic Chemistry)

1. What is typically meant by “oxidation” in organic chemistry?

A) Gain of electrons

B) Loss of electrons

C) Increase in the number of C–H bonds

D) Increase in the number of C–O bonds

E) Loss of oxygen atoms

2. Which of the following functional group transformations is considered an oxidation?

A) Alcohol → Alkene

B) Alcohol → Aldehyde

C) Ketone → Alcohol

D) Alkene → Alkane

E) Carboxylic acid → Aldehyde

3. What reagent is commonly used to oxidize primary alcohols to aldehydes?

A) PCC (pyridinium chlorochromate)

B) H₂/Pt

C) KMnO₄

D) HBr

E) HCl

4. What is the product when a primary alcohol is fully oxidized?

A) Ether

B) Aldehyde

C) Carboxylic acid

D) Ketone

E) Alkene

5. What is the typical product when a secondary alcohol is oxidized?

A) Aldehyde

B) Ether

C) Carboxylic acid

D) Ketone

E) Ester

6. Which of the following reagents is a strong oxidizing agent?

A) LiAlH₄

B) KMnO₄

C) H₂

D) BH₃

E) CH₃MgBr

7. Oxidation of an aldehyde typically forms a:

A) Ketone

B) Alcohol

C) Carboxylic acid

D) Ester

E) Alkene

8. Which of the following alcohols can be oxidized to a ketone?

A) Methanol

B) Ethanol

C) 1-propanol

D) 2-propanol

E) Benzyl alcohol

9. Which of the following cannot be oxidized further under normal conditions?

A) Primary alcohol

B) Aldehyde

C) Secondary alcohol

D) Ketone

E) Alkene

10. Which class of compound is least reactive toward oxidation?

A) Primary alcohol

B) Secondary alcohol

C) Tertiary alcohol

D) Aldehyde

E) Alkyne

11. What is the role of the oxidizing agent in an organic oxidation reaction?

A) Donates electrons

B) Accepts electrons

C) Breaks bonds only

D) Produces hydrogen gas

E) Neutralizes acids

12. Which of the following reactions involves oxidation?

A) CH₃CH₂OH → CH₃CHO

B) CH₃CH₂OH → CH₃CH₂Br

C) CH₃CH₂Cl → CH₃CH₂OH

D) CH₃CH₃ → CH₄ + CH₂

E) CH₃CHO → CH₃CH₂OH

13. Which of the following statements is correct about tertiary alcohols?

A) They are easily oxidized to ketones

B) They are oxidized to aldehydes

C) They do not undergo oxidation easily

D) They are oxidized to esters

E) They form acids when oxidized

14. Oxidation of 2-butanol produces:

A) Butanal

B) Butanoic acid

C) 2-butanone

D) Butene

E) Butyne

15. Which reaction condition will oxidize ethanol to acetic acid?

A) PCC in CH₂Cl₂

B) KMnO₄ under reflux

C) NaBH₄ in ethanol

D) H₂/Ni

E) HCl in water

16. What happens to the oxidation state of carbon during oxidation?

A) It decreases

B) It increases

C) It remains the same

D) It becomes zero

E) It becomes negative

17. Oxidation of a primary alcohol using KMnO₄ yields:

A) Alkene

B) Ketone

C) Aldehyde

D) Carboxylic acid

E) Amide

18. What is the color change observed when KMnO₄ oxidizes a compound?

A) Purple to brown

B) Colorless to blue

C) Red to yellow

D) Green to colorless

E) Orange to green

19. What happens to the hydrogen atoms during oxidation of alcohols?

A) They remain in the molecule

B) They form covalent bonds

C) They are removed

D) They turn into hydroxyl groups

E) They become part of the alkyl chain

20. Which of the following statements is true regarding oxidation reactions?

A) Only occur in the presence of acids

B) Always result in the formation of esters

C) Can increase the number of carbon-carbon bonds

D) Involve the addition of oxygen or removal of hydrogen

E) Only occur at high temperatures

Questions on Oxidation Reactions (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. D – In organic chemistry, oxidation is typically defined as increasing the number of C–O bonds or decreasing C–H bonds.

2. B – Converting an alcohol to an aldehyde increases oxidation state, thus it's an oxidation.

3. A – PCC oxidizes primary alcohols to aldehydes without further oxidation to carboxylic acids.

4. C – Full oxidation of a primary alcohol yields a carboxylic acid.

5. D – Secondary alcohols are oxidized to ketones.

6. B – KMnO₄ is a strong oxidizing agent, widely used in organic chemistry.

7. C – Aldehyde oxidation results in a carboxylic acid.

8. D – 2-propanol is a secondary alcohol, which oxidizes to 2-propanone (acetone).

9. D – Ketones generally do not oxidize under standard conditions.

10. C – Tertiary alcohols lack a hydrogen on the carbon bearing the OH, making them resistant to oxidation.

11. B – Oxidizing agents accept electrons, facilitating oxidation.

12. A – CH₃CH₂OH to CH₃CHO is an oxidation (loss of hydrogen/gain of oxygen).

13. C – Tertiary alcohols are resistant to oxidation due to lack of α-hydrogen.

14. C – 2-butanol (secondary) is oxidized to 2-butanone (a ketone).

15. B – Reflux with KMnO₄ provides full oxidation of ethanol to acetic acid.

16. B – During oxidation, carbon's oxidation state increases as it gains bonds to oxygen.

17. D – KMnO₄ oxidizes primary alcohols all the way to carboxylic acids.

18. A – KMnO₄ changes color from purple to brown as it is reduced.

19. C – Oxidation involves removal of hydrogen atoms.

20. D – Oxidation is the addition of oxygen or loss of hydrogen, a key definition.

Questions on Addition Reactions (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions on Addition Reactions (Organic Chemistry)

20 multiple-choice questions on Addition Reactions in Organic Chemistry, each with five answer choices (A–E). At the end, you’ll find a complete answer key with extended explanations.

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Multiple Choice Questions: Addition Reactions (Organic Chemistry)

1. What is an addition reaction?

A) A reaction where atoms are removed from a molecule

B) A reaction where atoms are added to a multiple bond

C) A reaction involving oxidation only

D) A substitution of hydrogen

E) A combustion reaction

2. Which types of compounds typically undergo addition reactions?

A) Alkanes

B) Aromatic rings

C) Saturated hydrocarbons

D) Alkenes and alkynes

E) Alcohols

3. What is formed when hydrogen is added to an alkene?

A) An alkyne

B) An aromatic compound

C) An alcohol

D) An alkane

E) A ketone

4. What catalyst is commonly used for the hydrogenation of alkenes?

A) HCl

B) NaOH

C) Pt or Pd

D) H₂O

E) FeCl₃

5. What is the product of the reaction of ethene with Br₂?

A) Ethyne

B) 1,2-dibromoethane

C) Ethanol

D) Ethanal

E) Bromobenzene

6. What type of addition reaction involves water adding to an alkene?

A) Hydration

B) Hydrolysis

C) Hydrogenation

D) Halogenation

E) Polymerization

7. In hydrohalogenation of alkenes, what is added across the double bond?

A) Water

B) A halogen molecule

C) H and OH

D) H and X (halogen)

E) Two H atoms

8. What is Markovnikov's rule?

A) The heavier atom adds to the more substituted carbon

B) The more electronegative atom bonds to the terminal carbon

C) In asymmetric alkenes, H adds to the carbon with more H atoms

D) H always adds to the more substituted carbon

E) OH adds to the carbon with fewer hydrogens

9. Which compound is formed when HBr is added to propene (CH₃CH=CH₂)?

A) CH₃CH₂CH₂Br

B) CH₃CHBrCH₃

C) CH₂BrCH₂CH₃

D) CH₃CH=CHBr

E) CH₃CH₂CHBr₂

10. What type of reaction is the addition of Cl₂ to cyclohexene?

A) Electrophilic substitution

B) Nucleophilic addition

C) Electrophilic addition

D) Free radical substitution

E) Oxidation

11. Which of the following is not an addition reaction?

A) Halogenation of an alkene

B) Hydration of an alkene

C) Hydrogenation of an alkene

D) Combustion of an alkene

E) Hydrohalogenation of an alkene

12. What is the first step in the electrophilic addition mechanism to an alkene?

A) Formation of carbocation

B) Nucleophile attack

C) Double bond breaks

D) Electrophile attacks the double bond

E) Formation of alkyl halide

13. Which of the following is an example of anti-Markovnikov addition?

A) HCl addition to ethene

B) HBr addition to propene with peroxide

C) Br₂ addition to ethene

D) Water addition to 2-butene

E) H₂ addition to alkyne

14. Which of the following reagents is required for hydration of an alkene?

A) H₂O and H₂SO₄

B) NaOH and H₂

C) Br₂ and CHCl₃

D) Cl₂ and UV light

E) NaBH₄ and H₂O

15. Which of the following is true about addition reactions?

A) They decrease the saturation of molecules

B) They involve only oxygen atoms

C) They increase saturation

D) They occur only with alkynes

E) They are reversible

16. The addition of hydrogen halides to unsymmetrical alkenes follows which rule?

A) Hund’s Rule

B) Le Chatelier’s Principle

C) Markovnikov’s Rule

D) Boyle’s Law

E) Dalton’s Law

17. What product is formed when H₂ is added to 2-butene in the presence of a Pt catalyst?

A) 1-butene

B) 2-butyne

C) Butane

D) 2-butanol

E) 2-bromobutane

18. What type of bond is broken in addition reactions to alkenes?

A) Sigma bond

B) Pi bond

C) Hydrogen bond

D) Ionic bond

E) Covalent polar bond

19. Which product is expected from the halogenation of 1-butene with Br₂?

A) 1-bromo-2-butene

B) 2,3-dibromobutane

C) 1,1-dibromobutane

D) 1,2-dibromobutane

E) Butadiene

20. What is the effect of peroxide in the addition of HBr to alkenes?

A) Speeds up the reaction

B) Causes the addition to follow Markovnikov’s rule

C) Converts the reaction into elimination

D) Causes the reaction to follow anti-Markovnikov’s rule

E) No effect at all

Questions on Addition Reactions (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. B – Addition reactions involve adding atoms to a multiple bond, typically a double or triple bond.

2. D – Alkenes and alkynes, which are unsaturated, undergo addition.

3. D – Adding hydrogen to an alkene results in an alkane.

4. C – Catalysts like Pt (platinum) or Pd (palladium) are used in hydrogenation.

5. B – Ethene + Br₂ → 1,2-dibromoethane, via electrophilic addition.

6. A – Adding water to alkenes is called hydration.

7. D – H and X (halogen) are added in hydrohalogenation.

8. C – Markovnikov’s rule: the hydrogen adds to the carbon with more hydrogens.

9. B – HBr + propene follows Markovnikov’s rule, forming CH₃CHBrCH₃.

10. C – Cl₂ addition to alkenes is electrophilic addition.

11. D – Combustion is not an addition reaction; it’s a redox process.

12. D – The first step is attack of electrophile on the double bond.

13. B – In the presence of peroxides, HBr adds in anti-Markovnikov fashion.

14. A – Hydration requires H₂O and an acid catalyst (like H₂SO₄).

15. C – Addition reactions increase saturation by converting double/triple bonds to single.

16. C – Markovnikov’s rule governs addition to unsymmetrical alkenes.

17. C – Hydrogenation of 2-butene yields butane.

18. B – The pi bond of the alkene is broken in addition reactions.

19. D – Br₂ adds across the double bond of 1-butene → 1,2-dibromobutane.

20. D – Peroxides make HBr add in anti-Markovnikov orientation.

Questions about Substitution Reactions (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions about Substitution Reactions (Organic Chemistry)

20 multiple-choice questions about Substitution Reactions in Organic Chemistry, each with five alternatives (A–E). The correct answers with extended explanations are provided at the end.

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Multiple Choice Questions: Substitution Reactions (Organic Chemistry)

1. What is a substitution reaction?

A) A reaction where atoms are added to a molecule

B) A reaction where one atom or group replaces another

C) A reaction forming a polymer

D) A reaction involving only metals

E) A redox reaction involving oxygen

2. Which of the following is a typical nucleophile in substitution reactions?

A) H⁺

B) Cl⁻

C) CH₄

D) CO₂

E) Fe³⁺

3. In an SN1 reaction, what is the rate-determining step?

A) Attack of the nucleophile

B) Formation of the carbocation

C) Elimination of the base

D) Leaving group departure and nucleophile attack simultaneously

E) Rearrangement of alkyl group

4. Which of the following best describes an SN2 reaction mechanism?

A) Two-step with carbocation intermediate

B) Radical intermediate formation

C) One-step with backside attack

D) Elimination of HX

E) Formation of a double bond

5. What kind of solvent is preferred for SN1 reactions?

A) Nonpolar

B) Aprotic

C) Polar protic

D) Gaseous

E) Basic

6. Which of the following halides is most reactive in SN1 substitution?

A) Methyl chloride

B) Ethyl chloride

C) Propyl chloride

D) tert-Butyl chloride

E) Vinyl chloride

7. Which factor increases the rate of SN2 reactions?

A) Steric hindrance

B) Tertiary carbon

C) Polar protic solvent

D) Strong nucleophile

E) Stable carbocation

8. What type of product is formed in nucleophilic substitution reactions?

A) An alkene

B) An ether

C) A substituted compound

D) A polymer

E) A metal complex

9. In which reaction is inversion of configuration observed?

A) SN1

B) SN2

C) E1

D) Addition reaction

E) Aromatic substitution

10. Which of the following groups is a poor leaving group?

A) Cl⁻

B) Br⁻

C) I⁻

D) OH⁻

E) Tosylate

11. Which type of carbon center is most favorable for SN2 reactions?

A) Primary

B) Secondary

C) Tertiary

D) Allylic

E) Benzylic

12. What is the typical order of reactivity for SN2 (from fastest to slowest)?

A) Tertiary > Secondary > Primary

B) Primary > Secondary > Tertiary

C) Secondary > Primary > Tertiary

D) Primary > Tertiary > Secondary

E) Tertiary > Primary > Secondary

13. Why are tertiary halides unsuitable for SN2 reactions?

A) Lack of nucleophile

B) Too acidic

C) High steric hindrance

D) Not reactive

E) Unstable leaving group

14. What is the molecularity of an SN1 reaction?

A) Unimolecular

B) Bimolecular

C) Trimolecular

D) Tetramolecular

E) Depends on solvent

15. Which condition favors SN2 over SN1?

A) Polar protic solvent

B) Weak nucleophile

C) Tertiary alkyl halide

D) Polar aprotic solvent

E) High temperature

16. What is the common feature of good leaving groups?

A) High basicity

B) Large atomic radius and low electronegativity

C) Ability to stabilize negative charge

D) Strong nucleophilicity

E) Poor solubility

17. What happens to the reaction rate of SN1 if the concentration of the nucleophile is doubled?

A) It doubles

B) It triples

C) It stays the same

D) It is halved

E) It drops to zero

18. What type of substitution occurs in the reaction of benzene with Cl₂ in the presence of FeCl₃?

A) Nucleophilic aliphatic substitution

B) Electrophilic aromatic substitution

C) Free radical substitution

D) SN2

E) E1

19. Which class of substitution involves a nucleophile and is typical of alkyl halides?

A) Electrophilic substitution

B) Nucleophilic substitution

C) Aromatic substitution

D) Redox substitution

E) Acyl substitution

20. Which of the following is a common example of an SN2 reaction?

A) Reaction of tert-butyl bromide with water

B) Reaction of methyl bromide with hydroxide ion

C) Bromination of benzene

D) Formation of carbocation from propyl chloride

E) Dehydration of alcohol

Questions about Substitution Reactions (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. B – Substitution involves replacing one atom or group with another.

2. B – Cl⁻ is a common nucleophile in substitution.

3. B – SN1 rate-determining step is formation of the carbocation.

4. C – SN2 is a one-step process with backside attack.

5. C – SN1 prefers polar protic solvents to stabilize intermediates.

6. D – Tert-butyl chloride forms a stable carbocation, making it best for SN1.

7. D – Strong nucleophiles increase SN2 rates.

8. C – Product is a substituted organic molecule.

9. B – SN2 causes inversion due to backside attack.

10. D – OH⁻ is a poor leaving group unless protonated or modified.

11. A – SN2 works best with primary carbons due to low steric hindrance.

12. B – SN2: Primary > Secondary > Tertiary.

13. C – Steric hindrance prevents SN2 on tertiary carbons.

14. A – SN1 is unimolecular, depends only on alkyl halide concentration.

15. D – Polar aprotic solvents favor SN2 reactions.

16. C – Good leaving groups stabilize negative charge, like I⁻, Br⁻.

17. C – SN1 rate does not depend on nucleophile concentration.

18. B – Benzene + Cl₂ with FeCl₃ = electrophilic aromatic substitution.

19. B – Alkyl halides undergo nucleophilic substitution.

20. B – Methyl bromide + OH⁻ → classic SN2 reaction.

Questions on Alkyl Halides (Organic Chemistry).

July 07, 2025 Organic Chemistry

Questions on Alkyl Halides (Organic Chemistry).

20 multiple-choice questions with five alternatives (A–E) on Alkyl Halides (Organic Chemistry). The correct answers and extended explanations are provided at the end.

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Multiple Choice Questions: Alkyl Halides (Organic Chemistry)

1. What is the general formula for an alkyl halide?

A) R–OH

B) R–COOH

C) R–X

D) R–NH₂

E) R–CHO

2. In alkyl halides, what does "X" represent?

A) Any metal

B) Oxygen or sulfur

C) Hydrogen

D) A halogen atom (F, Cl, Br, I)

E) A hydroxide ion

3. What is the IUPAC name of CH₃CH₂Cl?

A) Chloroethane

B) Ethyl chloride

C) Methyl chloride

D) Dichloroethane

E) Ethanol

4. Which of the following is a primary alkyl halide?

A) CH₃CHClCH₃

B) CH₃CH₂CH₂Cl

C) CH₃CCl₃

D) CCl₄

E) CH₃CH₂CH₂Br

5. Which of the following is a tertiary alkyl halide?

A) CH₃CH₂Cl

B) (CH₃)₃CCl

C) CH₃CH₂CH₂Br

D) CH₃CH₂CH₂I

E) CH₃CHClCH₂CH₃

6. Which hybridization does the carbon bonded to the halogen usually have in alkyl halides?

A) sp

B) sp²

C) sp³

D) dsp²

E) sp³d

7. Which of the following solvents would best promote an SN1 reaction in alkyl halides?

A) Hexane

B) Benzene

C) Water

D) Cyclohexane

E) Ether

8. What type of mechanism involves a carbocation intermediate?

A) SN2

B) E2

C) E1

D) SN1

E) Free radical substitution

9. Which of the following alkyl halides is most reactive in SN1 reactions?

A) Methyl chloride

B) Ethyl chloride

C) Isopropyl bromide

D) tert-Butyl bromide

E) Vinyl chloride

10. In an SN2 reaction, the reaction rate depends on:

A) Only the alkyl halide

B) Only the nucleophile

C) Temperature only

D) Both nucleophile and alkyl halide

E) Catalyst concentration

11. Which halide is the best leaving group?

A) F⁻

B) Cl⁻

C) Br⁻

D) I⁻

E) OH⁻

12. What is the major product when CH₃CH₂Br reacts with aqueous NaOH?

A) Ethene

B) Ethanol

C) Ethanal

D) Methanol

E) Acetic acid

13. What kind of reaction is it when an alkyl halide reacts with a nucleophile?

A) Elimination

B) Substitution

C) Polymerization

D) Combustion

E) Condensation

14. What is the hybridization of the carbon in methyl chloride (CH₃Cl)?

A) sp

B) sp²

C) sp³

D) sp³d

E) sp²d

15. What happens to the boiling point of alkyl halides with increasing molecular weight?

A) Decreases

B) Increases

C) Remains constant

D) First increases then decreases

E) Not predictable

16. Which factor does NOT affect SN1 reactivity?

A) Carbocation stability

B) Nature of the leaving group

C) Concentration of nucleophile

D) Solvent polarity

E) Structure of alkyl halide

17. What is formed when a tertiary alkyl halide undergoes elimination (E1)?

A) Ether

B) Alkene

C) Alcohol

D) Ester

E) Halohydrin

18. Which statement is true about alkyl halides?

A) They are nonpolar

B) They have low boiling points

C) They are highly reactive due to the electronegative halogen

D) They are soluble in water

E) They contain nitrogen

19. What type of bond is formed between carbon and halogen in alkyl halides?

A) Ionic bond

B) Hydrogen bond

C) Covalent polar bond

D) Nonpolar covalent bond

E) Coordinate bond

20. Which of the following is NOT an application of alkyl halides?

A) Solvent in organic reactions

B) Production of refrigerants

C) Fuel additive

D) DNA replication

E) Anesthetic production

Questions on Alkyl Halides (Organic Chemistry).

✅ Answer Key with Extended Explanations

1. C – Alkyl halides have the general formula R–X, where X is a halogen.

2. D – In alkyl halides, X represents halogens: F, Cl, Br, or I.

3. A – CH₃CH₂Cl is named chloroethane in IUPAC.

4. B – CH₃CH₂CH₂Cl is a primary alkyl halide; the halogen is attached to a primary carbon.

5. B – (CH₃)₃CCl is tertiary; the carbon bearing the halogen is bonded to three other carbon atoms.

6. C – The carbon in alkyl halides is sp³ hybridized.

7. C – Water is a polar protic solvent that stabilizes carbocations, favoring SN1.

8. D – SN1 reactions involve a carbocation intermediate.

9. D – tert-Butyl bromide forms the most stable carbocation, making it ideal for SN1.

10. D – SN2 reactions are bimolecular, depending on both nucleophile and alkyl halide.

11. D – Iodide (I⁻) is the best leaving group due to its size and low basicity.

12. B – CH₃CH₂Br + NaOH → CH₃CH₂OH (ethanol) in substitution.

13. B – Reaction of an alkyl halide with a nucleophile is a nucleophilic substitution.

14. C – Carbon in CH₃Cl is sp³ hybridized.

15. B – Boiling points increase with molecular weight due to greater van der Waals forces.

16. C – In SN1, nucleophile strength is not critical, as it's a two-step reaction.

17. B – E1 reactions on tertiary halides form alkenes.

18. C – Alkyl halides are reactive due to the polar C–X bond.

19. C – The C–X bond is polar covalent due to electronegativity difference.

20. D – Alkyl halides are not involved in DNA replication.

Questions on Amines (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions on Amines (Organic Chemistry)

20 multiple-choice questions with five alternatives (A–E) on Amines (Organic Chemistry). The correct answers and extended explanations are provided at the end.

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Multiple Choice Questions: Amines (Organic Chemistry)

1. What is the general formula of a primary amine?

A) R–NH–R'

B) R–NH₂

C) R–N⁺H₃

D) R–CH₂NH₂

E) R–COOH

2. Which of the following functional groups characterizes amines?

A) –OH

B) –CHO

C) –COOH

D) –NH₂

E) –CO–

3. What is the IUPAC name of CH₃NH₂?

A) Methanamine

B) Methylamine

C) Aminomethane

D) Ammonia

E) Methanoic acid

4. Amines are derivatives of which inorganic compound?

A) Water

B) Ammonia

C) Hydrochloric acid

D) Methane

E) Carbon dioxide

5. Which of the following is a secondary amine?

A) CH₃NH₂

B) (CH₃)₂NH

C) CH₃CH₂CH₂NH₂

D) NH₃

E) CH₃CH₂NHCH₂CH₃

6. Which of the following is true about tertiary amines?

A) They have one alkyl group attached to nitrogen

B) They have two hydrogen atoms on nitrogen

C) They cannot form hydrogen bonds with water

D) They have three alkyl or aryl groups attached to nitrogen

E) They contain a carbonyl group

7. Amines are classified based on:

A) The number of nitrogen atoms

B) The number of carbon atoms

C) The number of hydrogen atoms attached to nitrogen

D) The pH of the solution

E) Their boiling points

8. What type of amine is CH₃CH₂NHCH₃?

A) Primary

B) Secondary

C) Tertiary

D) Quaternary

E) Amide

9. What is the basicity of amines due to?

A) Oxygen lone pair

B) The lone pair of electrons on nitrogen

C) π-bond delocalization

D) Hydrogen bonding

E) Resonance with carbonyl group

10. Which of the following is a typical reaction involving amines?

A) Esterification

B) Dehydration

C) Acid-base reaction

D) Combustion

E) Saponification

11. What happens when an amine reacts with hydrochloric acid?

A) Forms an ester

B) Forms an amide

C) Forms a salt

D) Forms a ketone

E) Forms a hydrocarbon

12. What is the general trend of boiling points among primary, secondary, and tertiary amines?

A) Tertiary > Secondary > Primary

B) Primary > Secondary > Tertiary

C) All have the same boiling point

D) Depends only on molecular weight

E) Tertiary > Primary > Secondary

13. Which of the following compounds contains an aromatic amine?

A) CH₃NH₂

B) CH₃CH₂NHCH₃

C) C₆H₅NH₂

D) (CH₃)₃N

E) NH₃

14. Which naming suffix is used for amines in IUPAC nomenclature?

A) –oic acid

B) –ol

C) –al

D) –amine

E) –one

15. What is the hybridization of nitrogen in a simple amine?

A) sp

B) sp²

C) sp³

D) dsp²

E) sp²d

16. Amines can act as:

A) Only acids

B) Neither acids nor bases

C) Only oxidizing agents

D) Weak bases

E) Strong acids

17. What happens when an amine reacts with an acyl chloride?

A) Alcohol is formed

B) Amide is formed

C) Ester is formed

D) Hydrocarbon is formed

E) Nitrile is formed

18. What is the solubility trend of lower aliphatic amines in water?

A) Insoluble

B) Slightly soluble

C) Soluble due to hydrogen bonding

D) Soluble only in acids

E) Soluble only in alcohol

19. Which of the following describes aniline?

A) Aromatic aldehyde

B) Aromatic amide

C) Aromatic ketone

D) Aromatic amine

E) Aliphatic amine

20. Which physical property decreases from primary to tertiary amines?

A) Volatility

B) Solubility in water

C) Molecular weight

D) Reactivity

E) Nitrogen content

✅ Answer Key with Extended Explanations

1. B – A primary amine has one alkyl or aryl group and two hydrogen atoms on nitrogen: R–NH₂.

2. D – Amines contain the –NH₂ group (primary), or substituted variants.

3. A – CH₃NH₂ is methanamine in IUPAC, also called methylamine (common name).

4. B – Amines are derived from ammonia (NH₃) by replacing hydrogen atoms with alkyl or aryl groups.

5. B – (CH₃)₂NH is a secondary amine, with two alkyl groups on nitrogen.

6. D – Tertiary amines have three carbon-containing groups bonded to the nitrogen.

7. C – Amines are classified by the number of hydrogen atoms replaced on nitrogen.

8. B – CH₃CH₂NHCH₃ is a secondary amine (ethylmethylamine).

9. B – The basicity comes from the lone pair of electrons on nitrogen, which can accept a proton.

10. C – Amines react with acids in acid-base neutralization reactions.

11. C – Amines react with HCl to form ammonium salts.

12. B – Primary amines form more hydrogen bonds, giving them higher boiling points than tertiary.

13. C – C₆H₅NH₂ (aniline) is an aromatic amine.

14. D – The suffix for amines in IUPAC naming is –amine.

15. C – Nitrogen in amines is sp³ hybridized.

16. D – Amines are weak bases, due to the lone pair on nitrogen.

17. B – Amine + acyl chloride → amide.

18. C – Lower aliphatic amines are soluble in water due to hydrogen bonding.

19. D – Aniline is an aromatic amine (phenylamine).

20. B – Hydrogen bonding decreases from primary to tertiary amines, reducing solubility in water.

Questions about Esters (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions about Esters (Organic Chemistry)

20 multiple-choice questions about Esters (Organic Chemistry), each with five alternatives (A–E). The correct answers and extended explanations are provided at the end.

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Multiple Choice Questions: Esters (Organic Chemistry)

1. What is the general structure of an ester?

A) R–COOH

B) R–CO–R'

C) R–COO–R'

D) R–CH₂OH

E) R–NH₂

2. What two types of compounds react to form an ester?

A) Alcohol and ketone

B) Carboxylic acid and alcohol

C) Aldehyde and alcohol

D) Alcohol and amine

E) Ether and acid

3. What is the name of the ester formed from methanol and ethanoic acid?

A) Ethyl methanoate

B) Methylethanoate

C) Ethyl acetate

D) Methyl acetate

E) Methanoic acid

4. What is the typical reaction used to form esters?

A) Hydrolysis

B) Elimination

C) Esterification

D) Combustion

E) Nitration

5. What is produced during esterification along with the ester?

A) Alcohol

B) Water

C) Acid

D) Carbon dioxide

E) Hydrogen gas

6. Which functional group characterizes esters?

A) –COOH

B) –CHO

C) –OH

D) –COO–

E) –NH₂

7. What is the IUPAC name for CH₃COOCH₃?

A) Methyl acetate

B) Ethyl formate

C) Methanoic acid

D) Acetone

E) Methyl methanoate

8. What is the characteristic odor of many esters?

A) Pungent

B) Sulfur-like

C) Fruity

D) Metallic

E) Odorless

9. What is the product of the hydrolysis of an ester in acidic conditions?

A) Alcohol and carboxylic acid

B) Aldehyde and alcohol

C) Alkane and ketone

D) Alcohol and amine

E) Alcohol and ether

10. Esters can be saponified. What is the product of saponification?

A) Alcohol and ketone

B) Aldehyde and water

C) Salt of the acid and alcohol

D) Ester and water

E) Amide and acid

11. What is the main difference between esterification and hydrolysis?

A) One involves oxygen, the other does not

B) They are reverse processes

C) One requires a catalyst, the other doesn't

D) Only hydrolysis involves alcohol

E) Esterification involves amines

12. In naming esters, which part is derived from the alcohol?

A) The suffix

B) The prefix

C) The acid part

D) The root

E) The –COO–

13. Which ester is formed from ethanol and butanoic acid?

A) Butyl ethanoate

B) Ethyl butanoate

C) Ethyl ethanoate

D) Butanoic ethanoate

E) Ethanoic butanoate

14. Which of the following is NOT true about esters?

A) They are polar

B) They undergo hydrolysis

C) They are always solids at room temperature

D) They can be formed from acids and alcohols

E) They often have pleasant smells

15. Which catalyst is commonly used in esterification reactions?

A) Sodium hydroxide

B) Potassium permanganate

C) Concentrated sulfuric acid

D) Acetic acid

E) Sodium carbonate

16. What is the purpose of sulfuric acid in esterification?

A) Base catalyst

B) Dehydrating agent and acid catalyst

C) Oxidizing agent

D) Reducing agent

E) Solvent

17. What is the ester formed from phenol and benzoic acid?

A) Phenyl benzoate

B) Benzoic phenolate

C) Benzyl phenylate

D) Benzoic acid phenol ester

E) Phenylbenzene

18. What kind of bond connects the two parts of an ester molecule?

A) Ether bond

B) Ionic bond

C) Hydrogen bond

D) Covalent ester linkage

E) Van der Waals bond

19. What happens to the boiling point of esters compared to their corresponding acids?

A) It is always higher

B) It is lower due to less hydrogen bonding

C) It is the same

D) It depends only on molar mass

E) It fluctuates randomly

20. Which of the following is a common use of esters?

A) Rocket fuel

B) Artificial flavors and fragrances

C) Fertilizer

D) Glass manufacturing

E) DNA sequencing

Questions about Esters (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. C – Esters have the structure R–COO–R', where R and R' are hydrocarbon chains.

2. B – Esters are formed by the reaction of carboxylic acids and alcohols.

3. D – Methanol + ethanoic acid → methyl acetate.

4. C – The process of forming esters is called esterification.

5. B – Esterification produces water as a byproduct.

6. D – The –COO– group is the defining feature of esters.

7. A – CH₃COOCH₃ is named methyl acetate.

8. C – Esters often smell fruity and are used in flavorings.

9. A – Acidic hydrolysis of an ester gives a carboxylic acid and an alcohol.

10. C – Saponification yields a salt of the acid (soap) and alcohol.

11. B – Hydrolysis and esterification are reverse reactions.

12. B – The prefix in the ester name comes from the alcohol.

13. B – Ethanol + butanoic acid → ethyl butanoate.

14. C – Many esters are liquids at room temperature, not always solids.

15. C – Concentrated sulfuric acid acts as the catalyst in esterification.

16. B – H₂SO₄ is both an acid catalyst and a dehydrating agent.

17. A – Phenol + benzoic acid → phenyl benzoate.

18. D – The covalent bond between –CO and –O forms the ester linkage.

19. B – Esters have lower boiling points than carboxylic acids due to less hydrogen bonding.

20. B – Esters are widely used in flavorings and fragrances due to their aromas.

Questions about Carboxylic Acids (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions about Carboxylic Acids (Organic Chemistry)

20 multiple-choice questions about Carboxylic Acids (Organic Chemistry), each with five alternatives (A–E). The correct answers with extended explanations are presented at the end.

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Multiple Choice Questions: Carboxylic Acids (Organic Chemistry)

1. What is the functional group of carboxylic acids?

A) –CO–

B) –COOH

C) –OH

D) –CHO

E) –O–

2. What is the IUPAC name of HCOOH?

A) Ethanoic acid

B) Methanoic acid

C) Propanoic acid

D) Formic acid

E) Acetic acid

3. What is the common name of CH₃COOH?

A) Methanoic acid

B) Acetone

C) Acetic acid

D) Formic acid

E) Propanoic acid

4. What is the typical reaction of carboxylic acids with bases?

A) Substitution

B) Combustion

C) Neutralization

D) Addition

E) Elimination

5. What is the product of a reaction between a carboxylic acid and an alcohol?

A) Ketone

B) Amide

C) Ether

D) Ester

E) Aldehyde

6. What is the IUPAC name of CH₃CH₂COOH?

A) Methanoic acid

B) Ethanoic acid

C) Propanoic acid

D) Butanoic acid

E) Acetic acid

7. What is the acidity of carboxylic acids primarily due to?

A) Presence of hydroxyl group

B) Resonance stabilization of carboxylate ion

C) Hydrogen bonding

D) Large molecular weight

E) Carbonyl group only

8. Which of the following compounds is a dicarboxylic acid?

A) Citric acid

B) Formic acid

C) Oxalic acid

D) Acetone

E) Methanol

9. What is the boiling point behavior of carboxylic acids?

A) Very low

B) Similar to alkanes

C) Higher due to strong hydrogen bonding

D) Always gaseous

E) Lower than alcohols

10. Carboxylic acids are typically:

A) Basic

B) Neutral

C) Weak acids

D) Strong acids

E) Amphoteric

11. What is the result of oxidizing a primary alcohol completely?

A) Ether

B) Aldehyde

C) Ketone

D) Carboxylic acid

E) Ester

12. What does a carboxylic acid form when it reacts with a strong base?

A) Alkene

B) Salt and water

C) Alcohol

D) Amide

E) Aldehyde

13. Which of the following is NOT a carboxylic acid derivative?

A) Ester

B) Amide

C) Aldehyde

D) Acid chloride

E) Anhydride

14. What is the main intermolecular force in carboxylic acids?

A) Ionic bonding

B) Hydrogen bonding

C) Van der Waals forces

D) Metallic bonding

E) Dipole-dipole interactions only

15. What is the carboxylate ion?

A) The conjugate base of a carboxylic acid

B) A form of alcohol

C) A neutral molecule

D) A gas

E) A hydrocarbon

16. What is the suffix used for naming carboxylic acids in IUPAC nomenclature?

A) –al

B) –one

C) –oic acid

D) –ol

E) –ate

17. What is the IUPAC name of CH₃CH₂CH₂COOH?

A) Butanoic acid

B) Propanoic acid

C) Pentanoic acid

D) Ethanoic acid

E) Methanoic acid

18. What happens to a carboxylic acid in aqueous solution?

A) It ionizes partially

B) It ionizes completely

C) It forms an ester

D) It precipitates

E) It reacts with air

19. What is formed when acetic acid is treated with ethanol in the presence of sulfuric acid?

A) Acetone

B) Ethyl acetate

C) Acetamide

D) Acetaldehyde

E) Ethanol

20. What distinguishes a carboxylic acid from an aldehyde?

A) One has a hydroxyl group attached to the carbonyl carbon

B) One contains nitrogen

C) One is a base

D) One is cyclic

E) One is ionic

Questions about Carboxylic Acids (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. B – Carboxylic acids contain the –COOH (carboxyl) group.

2. B – HCOOH is methanoic acid (common name: formic acid).

3. C – CH₃COOH is acetic acid, a common weak acid in vinegar.

4. C – Carboxylic acids undergo neutralization with bases to form salts and water.

5. D – A carboxylic acid + alcohol forms an ester via esterification.

6. C – CH₃CH₂COOH is propanoic acid, a three-carbon acid.

7. B – The acidity is due to resonance stabilization of the carboxylate ion.

8. C – Oxalic acid has two carboxylic acid groups (–COOH).

9. C – Due to strong hydrogen bonding, carboxylic acids have high boiling points.

10. C – They are weak acids but stronger than alcohols or phenols.

11. D – Complete oxidation of a primary alcohol gives a carboxylic acid.

12. B – They form salts and water with strong bases.

13. C – Aldehydes are not carboxylic acid derivatives.

14. B – They form hydrogen bonds, especially dimers, increasing boiling point.

15. A – The carboxylate ion (RCOO⁻) is the conjugate base of a carboxylic acid.

16. C – IUPAC names use the suffix –oic acid for carboxylic acids.

17. A – CH₃CH₂CH₂COOH is butanoic acid (4-carbon chain).

18. A – They partially ionize in water, acting as weak acids.

19. B – Reaction of acetic acid + ethanol + H₂SO₄ yields ethyl acetate (ester).

20. A – Carboxylic acids have an –OH attached to the carbonyl carbon, unlike aldehydes.

Questions on Aldehydes and Ketones (Organic Chemistry)

July 07, 2025 Organic Chemistry

Questions on Aldehydes and Ketones (Organic Chemistry)

20 multiple-choice questions with five alternatives (A–E) on Aldehydes and Ketones (Organic Chemistry). At the end, you'll find the correct answers with extended explanations.

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Multiple Choice Questions: Aldehydes and Ketones

1. What is the functional group of aldehydes?

A) –OH

B) –COOH

C) –CHO

D) –CO–

E) –NH₂

2. What is the functional group of ketones?

A) –COOH

B) –CH₃

C) –CHO

D) –CO–

E) –OH

3. What is the IUPAC name of CH₃CHO?

A) Methanal

B) Ethanal

C) Propanal

D) Acetone

E) Methanoic acid

4. Which of the following is a ketone?

A) CH₃CH₂CH₂OH

B) CH₃COCH₃

C) CH₃CHO

D) CH₃COOH

E) CH₃CH₂NH₂

5. Which of the following is a property of aldehydes?

A) Cannot be oxidized

B) Cannot be reduced

C) Easily oxidized to carboxylic acids

D) Contain nitrogen atoms

E) Are bases

6. What is the common name of propanone?

A) Formaldehyde

B) Acetaldehyde

C) Acetone

D) Butanone

E) Ethanal

7. Which of the following contains the carbonyl group (>C=O)?

A) Alcohols

B) Aldehydes and ketones

C) Alkanes

D) Alkynes

E) Amines

8. Which of these is the correct classification of acetaldehyde?

A) Alcohol

B) Ketone

C) Ester

D) Aldehyde

E) Acid

9. Which of these tests can distinguish between an aldehyde and a ketone?

A) Bromine water

B) Tollens' test

C) Baeyer's test

D) Flame test

E) Benedict's test

10. Which reagent gives a silver mirror with aldehydes?

A) HCl

B) Br₂

C) Tollens' reagent

D) Fehling's solution

E) I₂

11. What is the product when a ketone is reduced?

A) Carboxylic acid

B) Alcohol

C) Ester

D) Amine

E) Aldehyde

12. Which of these is the IUPAC name for acetone?

A) Propanone

B) Butanone

C) Propanal

D) Acetaldehyde

E) Ethanol

13. What type of compound is CH₃CH₂COCH₃?

A) Aldehyde

B) Ketone

C) Carboxylic acid

D) Alcohol

E) Ester

14. What is the suffix used for naming aldehydes in IUPAC nomenclature?

A) –ol

B) –al

C) –one

D) –ic acid

E) –ane

15. What is the suffix used for naming ketones in IUPAC nomenclature?

A) –one

B) –al

C) –ic

D) –yl

E) –ate

16. What is the result of oxidation of an aldehyde?

A) Ketone

B) Ester

C) Alcohol

D) Carboxylic acid

E) Alkene

17. Which of the following carbonyl compounds is more reactive toward nucleophiles?

A) Ketones

B) Aldehydes

C) Carboxylic acids

D) Esters

E) Amides

18. What is the boiling point trend between aldehydes and ketones of similar size?

A) Aldehydes have much higher boiling points

B) Ketones have slightly higher boiling points

C) Aldehydes and ketones have equal boiling points

D) Aldehydes have higher boiling points than ketones

E) None of the above

19. Which intermolecular force is most important in pure liquid aldehydes and ketones?

A) Ionic bonding

B) Hydrogen bonding

C) Covalent bonding

D) Dipole–dipole interactions

E) Metallic bonding

20. Which of the following statements is TRUE about ketones?

A) They can be oxidized to carboxylic acids easily

B) They do not contain a carbonyl group

C) They have the general formula R–CO–R'

D) They give a positive Tollens' test

E) They are always solids at room temperature

Questions on Aldehydes and Ketones (Organic Chemistry)

✅ Answer Key with Extended Explanations

1. C – Aldehydes contain the –CHO group, a carbon double-bonded to oxygen and single-bonded to hydrogen.

2. D – Ketones contain the –CO– group (carbonyl) between two carbon atoms.

3. B – CH₃CHO is ethanal, a two-carbon aldehyde.

4. B – CH₃COCH₃ is propanone, a ketone with a central carbonyl group.

5. C – Aldehydes are easily oxidized to carboxylic acids (–COOH).

6. C – Acetone is the common name for propanone, a simple ketone.

7. B – Aldehydes and ketones both contain the carbonyl group (>C=O).

8. D – Acetaldehyde is the common name for ethanal, an aldehyde.

9. B – Tollens’ test distinguishes aldehydes (silver mirror test).

10. C – Tollens' reagent reacts with aldehydes to produce a silver mirror.

11. B – Reduction of a ketone produces a secondary alcohol.

12. A – Acetone = propanone (3-carbon ketone).

13. B – CH₃CH₂COCH₃ is a ketone, specifically butan-2-one.

14. B – Aldehydes are named with the suffix –al in IUPAC.

15. A – Ketones are named with the suffix –one in IUPAC.

16. D – Aldehydes are oxidized to carboxylic acids.

17. B – Aldehydes are more reactive than ketones due to less steric hindrance.

18. B – Ketones tend to have slightly higher boiling points than aldehydes.

19. D – Dipole–dipole interactions are significant due to the polar carbonyl group.

20. C – Ketones have the general formula R–CO–R'.