CUET UG Chemistry Booster Test - 3 Introduction & Nomenclature (Aldehydes and Ketones) -

🚀

CUET UG Chemistry Booster Test - 3 Introduction & Nomenclature (Aldehydes and Ketones)

⏱️ 30 Minutes

❓ 20 Questions

📌 Answers are locked once submitted — results and explanations appear at the end.

CUET UG Chemistry Booster Test - 3 Introduction & Nomenclature (Aldehydes and Ketones)

1 / 20

QUESTION 1 OF 20

Regarding the electronic properties of the carbonyl group:
1. It has high polarity explained on the basis of resonance involving neutral and dipolar structures.
2. The carbonyl carbon acts as an electrophilic Lewis acid.
3. It is non-polar compared to ethers.

Answer Review

1 Regarding the electronic properties of the carbonyl group:
1. It has high polarity explained on the basis of resonance involving neutral and dipolar structures.
2. The carbonyl carbon acts as an electrophilic Lewis acid.
3. It is non-polar compared to ethers.

A 1 and 2

B 1 and 3

C 2 and 3

D 1, 2 and 3

💡 Short Explanation

�� Carbonyl group is highly polar. �� Carbonyl carbon is electrophilic. �� Carbonyl compounds are more polar than ethers.

✅ Correct Answer Explanation

The carbonyl group exhibits resonance between a neutral structure and a dipolar structure, creating significant polarity. Due to the partial positive charge on carbon, the carbonyl carbon behaves as an electrophilic Lewis acid and readily undergoes nucleophilic attack.

❓ Why Other Options Are Incorrect

�� Statement 3 is incorrect because carbonyl compounds are polar.
�� Options B, C and D contain statement 3.

🎯 Strategy

Used

Concept Analysis

🧠 Memory Trick

C=O ⇒ Cδ⁺ and Oδ⁻.

📚 Aldehydes, Ketones and Carboxylic Acids – Electronic Nature of Carbonyl Group

2 Compounds in which the carbon of the carbonyl group is bonded to the nitrogen of an –NH₂ moiety are classified as:

A Acyl halides

B Amides

C Esters

D Ketones

💡 Short Explanation

�� Amides contain the –CONH₂ group. �� Carbonyl carbon is directly attached to nitrogen. �� They are carboxylic acid derivatives.

✅ Correct Answer Explanation

Amides have the general structure R–CONH₂, where the carbonyl carbon is bonded directly to a nitrogen atom of an amino group.

❓ Why Other Options Are Incorrect

�� Option A → Carbonyl attached to halogen.
�� Option C → Carbonyl attached to oxygen.
�� Option D → Carbonyl attached to two carbon atoms.

🎯 Strategy

Used

Functional Group Identification

🧠 Memory Trick

Amide = CO + NH₂.

📚 Aldehydes, Ketones and Carboxylic Acids – Carbonyl Derivatives

3 What fundamental sub-unit constitutes an aldehyde functional group?

A A carbonyl group (>C=O) attached to two alkyl groups

B A carbonyl group (>C=O) attached to a carbon and a hydrogen atom

C A carbonyl group (>C=O) attached to an –OH group

D A carbonyl group (>C=O) attached to a halogen

💡 Short Explanation

�� Aldehydes contain the –CHO group. �� Carbonyl carbon is bonded to hydrogen. �� Distinguishes aldehydes from ketones.

✅ Correct Answer Explanation

An aldehyde contains a carbonyl group in which the carbonyl carbon is bonded to at least one hydrogen atom. Its general structure is R–CHO.

❓ Why Other Options Are Incorrect

�� Option A → Ketone structure.
�� Option C → Carboxylic acid structure.
�� Option D → Acyl halide structure.

🎯 Strategy

Used

Functional Group Recognition

🧠 Memory Trick

Aldehyde = CHO.

📚 Aldehydes, Ketones and Carboxylic Acids – Functional Groups

4 A ketone group cannot exist at the terminal position of an open carbon chain because:

A It must be bonded to a hydrogen atom.

B It must be bonded to two carbon atoms.

C It involves a triple bond.

D It requires an sp³ hybridized carbon.

💡 Short Explanation

�� Ketone carbonyl carbon is internal. �� It must be attached to two carbon atoms. �� Terminal carbonyl gives an aldehyde.

✅ Correct Answer Explanation

In ketones, the carbonyl carbon is bonded to two carbon atoms. Therefore, the carbonyl group cannot occur at the end of an open-chain molecule.

❓ Why Other Options Are Incorrect

�� Option A → Characteristic of aldehydes.
�� Option C → Ketones contain no triple bond.
�� Option D → Carbonyl carbon is sp² hybridized.

🎯 Strategy

Used

Structure Analysis

🧠 Memory Trick

Ketone = C–CO–C.

📚 Aldehydes, Ketones and Carboxylic Acids – Ketone Structure

5 What is the common name of the naturally occurring aldehyde derived from vanilla beans?

A Cinnamaldehyde

B Salicylaldehyde

C Vanillin

D Acrolein

💡 Short Explanation

�� Vanilla beans contain vanillin. �� Responsible for vanilla fragrance. �� Naturally occurring aldehyde.

✅ Correct Answer Explanation

Vanillin is the naturally occurring aromatic aldehyde extracted from vanilla beans and is responsible for their characteristic aroma.

❓ Why Other Options Are Incorrect

�� Option A → Found in cinnamon.
�� Option B → Found in meadow sweet.
�� Option D → Unsaturated aldehyde.

🎯 Strategy

Used

Fact Recall

🧠 Memory Trick

Vanilla → Vanillin.

📚 Aldehydes, Ketones and Carboxylic Acids – Importance of Carbonyl Compounds

6 Which specific class of compounds are heavily utilized as starting materials for preparing adhesives, paints, and resins?

A Alkanes

B Carbonyl compounds

C Ethers

D Alkyl halides

💡 Short Explanation

�� Widely used in industry. �� Important raw materials. �� Used in adhesives, paints and resins.

✅ Correct Answer Explanation

Aldehydes, ketones and related carbonyl compounds are extensively used in manufacturing adhesives, paints, resins, plastics, pharmaceuticals and fragrances.

❓ Why Other Options Are Incorrect

�� Option A → Less commonly used for such applications.
�� Option C → Not primary industrial precursors here.
�� Option D → Mainly intermediates in organic synthesis.

🎯 Strategy

Used

Application Recall

🧠 Memory Trick

Carbonyl compounds = Industrial building blocks.

📚 Aldehydes, Ketones and Carboxylic Acids – Uses and Importance

7 Match the Latin source term with its corresponding common carboxylic acid/aldehyde derivation:

List-I	List-II
1. Formica (ant)	a. Formic acid
2. Acetum (vinegar)	b. Acetic acid
3. Butyrum (butter)	c. Butyric acid

A 1-a, 2-b, 3-c

B 1-b, 2-c, 3-a

C 1-c, 2-a, 3-b

D 1-a, 2-c, 3-b

💡 Short Explanation

�� Formica means ant. �� Acetum means vinegar. �� Butyrum means butter.

✅ Correct Answer Explanation

Latin Source — Derived Acid Formica (ant) — Formic acid Acetum (vinegar) — Acetic acid Butyrum (butter) — Butyric acid Therefore: 1-a, 2-b, 3-c

❓ Why Other Options Are Incorrect

�� Options B, C and D contain incorrect matching pairs.

🎯 Strategy

Used

Match the Following

🧠 Memory Trick

Ant → Formic, Vinegar → Acetic, Butter → Butyric.

📚 Aldehydes, Ketones and Carboxylic Acids – Common Names

8 The common name for the ketone CH₃COCH₂CH₂CH₃ is derived by naming the two alkyl groups bonded to the carbonyl group. What is it?

A Pentan-2-one

B Methyl n-propyl ketone

C Diethyl ketone

D Butanone

💡 Short Explanation

�� Ketone contains methyl and n-propyl groups. �� Common nomenclature uses alkyl group names. �� Followed by the word ketone.

✅ Correct Answer Explanation

The structure CH₃COCH₂CH₂CH₃ contains: One methyl group (CH₃–) One n-propyl group (CH₂CH₂CH₃) Hence the common name is: Methyl n-propyl ketone

❓ Why Other Options Are Incorrect

�� Option A → IUPAC name.
�� Option C → Represents pentan-3-one.
�� Option D → Incorrect carbon count.

🎯 Strategy

Used

Common Naming Analysis

🧠 Memory Trick

Name both alkyl groups + ketone.

📚 Aldehydes, Ketones and Carboxylic Acids – Common Names of Ketones

9 According to the passage, the carbon atom located exactly two positions away from the aldehyde group (next to alpha) is designated as:

A α-carbon

B β-carbon

C γ-carbon

D δ-carbon

💡 Short Explanation

�� Carbon directly attached to CHO = α-carbon. �� Next carbon = β-carbon. �� Greek letters indicate position.

✅ Correct Answer Explanation

The passage states: α-carbon → directly attached to aldehyde group β-carbon → next carbon after α γ-carbon → next after β Therefore, the carbon located next to α-carbon is the β-carbon.

❓ Why Other Options Are Incorrect

�� Option A → Directly attached carbon.
�� Option C → Third position away.
�� Option D → Fourth position away.

🎯 Strategy

Used

Passage-Based Recall

🧠 Memory Trick

α → β → γ → δ

📚 Aldehydes, Ketones and Carboxylic Acids – Common Nomenclature

10 If a substituent is attached to the carbon immediately adjacent to the carbonyl group in an aldehyde, its locant in the common system is:

A 1

B 2

C α

D β

💡 Short Explanation

�� Adjacent carbon is α-carbon. �� Greek letters are used in common nomenclature. �� α is nearest to carbonyl group.

✅ Correct Answer Explanation

In the common naming system, the carbon directly attached to the carbonyl carbon is called the α-carbon. Any substituent attached to this carbon is described using the α-locant.

❓ Why Other Options Are Incorrect

�� Options A and B are numerical locants used in IUPAC nomenclature.
�� Option D refers to the next carbon after α.

🎯 Strategy

Used

Passage-Based Concept

🧠 Memory Trick

Adjacent carbon = Alpha carbon.

📚 Aldehydes, Ketones and Carboxylic Acids – Greek Letter System for Common Names

11 For IUPAC naming of aliphatic open chain aldehydes, the longest carbon chain must:

A Exclude the carbonyl carbon

B Be numbered starting from the carbon of the aldehyde group

C Start from the end nearest to an alkyl substituent

D Start from the largest alkyl group

💡 Short Explanation

�� Aldehyde carbon always gets position 1. �� Numbering starts from the –CHO carbon. �� Ensures correct IUPAC nomenclature.

✅ Correct Answer Explanation

In aldehydes, the carbon atom of the aldehyde group is always included in the parent chain and is assigned carbon number 1. Therefore, numbering begins from the aldehyde carbon.

❓ Why Other Options Are Incorrect

�� Option A → Aldehyde carbon must be included.
�� Option C → Substituents do not determine numbering priority.
�� Option D → Largest alkyl group is irrelevant.

🎯 Strategy

Used

IUPAC Rule Recall

🧠 Memory Trick

CHO carbon = Carbon-1.

📚 Aldehydes, Ketones and Carboxylic Acids – IUPAC Nomenclature of Aldehydes

12 What is the IUPAC name for Diisopropyl ketone?

A 2,4-Dimethylpentan-3-one

B 2-Methylpentan-3-one

C 3-Methylpentan-2-one

D Heptan-4-one

💡 Short Explanation

�� Diisopropyl ketone contains two isopropyl groups. �� Longest chain has five carbon atoms. �� Ketone group is at carbon 3.

✅ Correct Answer Explanation

Structure: (CH₃)₂CH–CO–CH(CH₃)₂ The longest chain contains five carbons with the carbonyl carbon at position 3 and methyl substituents at positions 2 and 4. Hence the IUPAC name is: 2,4-Dimethylpentan-3-one

❓ Why Other Options Are Incorrect

�� Option B → Missing one methyl substituent.
�� Option C → Incorrect numbering.
�� Option D → Incorrect carbon skeleton.

🎯 Strategy

Used

IUPAC Structure Analysis

🧠 Memory Trick

Two isopropyl groups = methyls at C-2 and C-4.

📚 Aldehydes, Ketones and Carboxylic Acids – Ketone Nomenclature

13 Identify the correct numbering formatting rule for naming substituents on a branched aldehyde carbon chain.

A Prefixed in alphabetical order with numerals indicating positions

B Prefixed in increasing order of size

C Prefixed in decreasing order of atomic mass

D Placed as suffixes at the end of the name

💡 Short Explanation

�� Substituents are written as prefixes. �� Positions are indicated by locants. �� Alphabetical order is followed.

✅ Correct Answer Explanation

In IUPAC nomenclature, substituents are named as prefixes before the parent compound name. Their positions are indicated using numerals, and multiple substituents are arranged alphabetically.

❓ Why Other Options Are Incorrect

�� Option B → Size is not used.
�� Option C → Atomic mass is irrelevant.
�� Option D → Substituents are prefixes, not suffixes.

🎯 Strategy

Used

Nomenclature Rule Recall

🧠 Memory Trick

Alphabetical prefixes + locants.

📚 Aldehydes, Ketones and Carboxylic Acids – IUPAC Rules

14 Arrange the following steps for deriving the IUPAC name of an open-chain ketone in the correct logical sequence:
(A) Number the chain from the end nearer to the carbonyl group.
(B) Identify the longest continuous carbon chain containing the >C=O group.
(C) Replace the '-e' ending of the parent alkane with '-one'.
(D) Prefix substituents alphabetically with their numerals.

A (B), (C), (A), (D)

B (B), (A), (C), (D)

C (A), (B), (C), (D)

D (C), (B), (A), (D)

💡 Short Explanation

�� Find the parent chain first. �� Number from the carbonyl end. �� Convert alkane to ketone name. �� Add substituents last.

✅ Correct Answer Explanation

The correct sequence is: 1. Identify the longest chain containing C=O. 2. Number it from the end nearest to the carbonyl group. 3. Replace "-e" with "-one". 4. Add substituent names and locants alphabetically. Therefore: (B) → (A) → (C) → (D)

❓ Why Other Options Are Incorrect

�� Options A, C and D do not follow standard IUPAC procedure.

🎯 Strategy

Used

Ordering

🧠 Memory Trick

Chain → Number → One → Prefixes.

📚 Aldehydes, Ketones and Carboxylic Acids – Ketone Nomenclature

15 The common name α-Methylcyclohexanone has the systematic IUPAC name:

A 1-Methylcyclohexan-2-one

B 2-Methylcyclohexanone

C 3-Methylcyclohexanone

D Cyclohexyl methyl ketone

💡 Short Explanation

�� Carbonyl carbon is position 1. �� α-carbon is adjacent to carbonyl carbon. �� Methyl group is therefore at carbon 2.

✅ Correct Answer Explanation

In cyclohexanone, numbering begins at the carbonyl carbon. The α-carbon is the carbon directly adjacent to the carbonyl carbon, which corresponds to carbon 2. Hence: α-Methylcyclohexanone = 2-Methylcyclohexanone

❓ Why Other Options Are Incorrect

�� Option A → Incorrect locant assignment.
�� Option C → Methyl group would be at β-position.
�� Option D → Different naming system.

🎯 Strategy

Used

Cyclic Ketone Numbering

🧠 Memory Trick

α-position = Carbon-2.

📚 Aldehydes, Ketones and Carboxylic Acids – Cyclic Ketone Nomenclature

16 When naming cyclic compounds with an attached aldehyde group:
1. The suffix carbaldehyde is added after the full name of the cycloalkane.
2. The numbering of the ring starts from the carbon atom attached to the aldehyde group.
3. It is named identically to open-chain aldehydes using the suffix -al.

A 1 and 2

B 1 and 3

C 2 and 3

D 1, 2 and 3

💡 Short Explanation

�� Cyclic aldehydes use the suffix "carbaldehyde". �� Ring numbering starts at the carbon attached to CHO. �� Suffix "-al" is not used directly.

✅ Correct Answer Explanation

For aldehydes attached directly to a cycloalkane ring, the suffix carbaldehyde is used. The carbon attached to the aldehyde group is assigned position 1 for numbering purposes.

❓ Why Other Options Are Incorrect

�� Statement 3 is incorrect.
�� Open-chain aldehydes use "-al", whereas cyclic aldehydes use "carbaldehyde".
�� Options B, C and D include statement 3.

🎯 Strategy

Used

Statement Analysis

🧠 Memory Trick

Ring + CHO = Carbaldehyde.

📚 Aldehydes, Ketones and Carboxylic Acids – Cyclic Aldehyde Nomenclature

17 The compound Phthaldehyde consists of a benzene ring with two aldehyde groups. Its IUPAC name is:

A Benzenecarbaldehyde

B Benzene-1,2-dicarbaldehyde

C Benzene-1,3-dicarbaldehyde

D Benzene-1,4-dicarbaldehyde

💡 Short Explanation

�� Phthaldehyde is the ortho isomer. �� Aldehyde groups occupy positions 1 and 2. �� Hence "1,2-dicarbaldehyde".

✅ Correct Answer Explanation

Phthaldehyde contains two aldehyde groups attached to adjacent carbon atoms of a benzene ring (ortho arrangement). Therefore, its IUPAC name is: Benzene-1,2-dicarbaldehyde

❓ Why Other Options Are Incorrect

�� Option A → Contains only one aldehyde group.
�� Option C → Meta isomer.
�� Option D → Para isomer.

🎯 Strategy

Used

Aromatic Compound Identification

🧠 Memory Trick

Phthal = Ortho = 1,2.

📚 Aldehydes, Ketones and Carboxylic Acids – Aromatic Aldehydes

18 In naming substituted benzaldehydes via IUPAC rules, the ring numbering assigns position 1 to:

A The carbon with a halogen substituent

B The carbon bearing the aldehyde group

C The carbon with an alkyl group

D Any arbitrary carbon

💡 Short Explanation

�� Aldehyde group has highest priority. �� Carbon attached to CHO becomes carbon-1. �� All other substituents are numbered relative to it.

✅ Correct Answer Explanation

For substituted benzaldehydes, numbering starts from the carbon atom directly attached to the aldehyde group because it is the principal functional group.

❓ Why Other Options Are Incorrect

�� Options A and C have lower priority.
�� Option D violates IUPAC rules.

🎯 Strategy

Used

Priority Rule Application

🧠 Memory Trick

CHO always gets position 1.

📚 Aldehydes, Ketones and Carboxylic Acids – Aromatic Nomenclature

19 Mesityl oxide has the corresponding IUPAC name:

A 4-Methylpent-3-en-2-one

B 2-Methylpentan-3-one

C 3-Methylpent-2-en-4-one

D Pentan-2-one

💡 Short Explanation

�� Mesityl oxide is an α,β-unsaturated ketone. �� Contains five carbons. �� Has one methyl substituent and one double bond.

✅ Correct Answer Explanation

Mesityl oxide has the structure: CH₃COCH=C(CH₃)CH₃ The correct IUPAC name is: 4-Methylpent-3-en-2-one

❓ Why Other Options Are Incorrect

�� Option B → Saturated ketone.
�� Option C → Incorrect numbering.
�� Option D → No double bond or methyl substituent.

🎯 Strategy

Used

IUPAC Structure Recognition

🧠 Memory Trick

Mesityl oxide = Unsaturated ketone.

📚 Aldehydes, Ketones and Carboxylic Acids – Examples of Carbonyl Compounds

20 Match the Common Name with the correct IUPAC Name from the examples table:

List-I	List-II
1. Isobutyraldehyde	a. 2-Methylpropanal
2. Valeraldehyde	b. Pentanal
3. Acrolein	c. Prop-2-enal

A 1-a, 2-b, 3-c

B 1-b, 2-a, 3-c

C 1-c, 2-b, 3-a

D 1-a, 2-c, 3-b

💡 Short Explanation

�� Isobutyraldehyde → 2-Methylpropanal. �� Valeraldehyde → Pentanal. �� Acrolein → Prop-2-enal.

✅ Correct Answer Explanation

Common Name — IUPAC Name Isobutyraldehyde — 2-Methylpropanal Valeraldehyde — Pentanal Acrolein — Prop-2-enal Therefore: 1-a, 2-b, 3-c

❓ Why Other Options Are Incorrect

�� Options B, C and D contain incorrect pairings.

🎯 Strategy

Used

Match the Following

🧠 Memory Trick

Acrolein = Prop-2-enal.

📚 Aldehydes, Ketones and Carboxylic Acids – Common Names vs IUPAC Names

CUET UG Chemistry Booster Test – 3 Introduction & Nomenclature (Aldehydes and Ketones)

CUET UG Chemistry Booster Test - 3 Introduction & Nomenclature (Aldehydes and Ketones)

Test Complete!

Answer Review