CUET UG Chemistry Booster Test - 3 Nomenclature
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QUESTION 1 OF 20
When distinguishing common naming structures, what conceptual difference separates an isobutyl group from a sec-butyl group in alcohols?
QUESTION 2 OF 20
Which of the following strictly adhere to the IUPAC rules for naming alcohols?
1. In polyhydric alcohols, the 'e' of alkane is retained and ending 'ol' added.
2. The position of substituents are indicated using numerals determined by proximity to the hydroxyl group.
3. 'Cyclo' is added before the parent chain of any alcohol containing a benzene ring.
4. Multiplicative prefixes do not alter the retention of the 'e' in polyhydric species.
QUESTION 3 OF 20
What is the IUPAC name of the complex unsaturated alcohol CH₂=CH–CH(OH)–CH₃?
QUESTION 4 OF 20
Arrange the sequence of the substituent locants in ascending numerical order for the molecule 4-Chloro-3-ethyl-2-(1-methylethyl)-butan-1-ol:
1. Chloro
2. (1-methylethyl)
3. Ethyl
4. Hydroxyl (ol)
QUESTION 5 OF 20
In compounds containing both a double bond and a hydroxyl group (e.g., Hex-1-en-3-ol):
1. The alkene gets numbering priority over the hydroxyl group.
2. The hydroxyl group gets numbering priority, dictating the end from which the chain is numbered.
3. The suffix 'en' comes before 'ol' in the final name.
4. The parent chain must contain both the double bond and the hydroxyl carbon.
QUESTION 6 OF 20
Match List I with List II.
| List I | List II |
|---|---|
| 1. 4-Chloro-2,3-dimethylpentan-1-ol | a. A diol with methyls at C-2 and C-5 |
| 2. 2-Ethoxy-1,1-dimethylcyclohexane | b. An ether with a nitro group at C-2 |
| 3. 1-Ethoxy-2-nitrocyclohexane | c. A primary alcohol with chloro at C-4 |
| 4. 2,5-Dimethylhexane-1,3-diol | d. A cyclic ether with gem-dimethyls at C-1 |
QUESTION 7 OF 20
The IUPAC name of the heavily substituted diol structure CH₃–CH(CH₃)–CH₂–CH(OH)–CH(CH₃)–CH₂–OH is:
QUESTION 8 OF 20
Why is the formal IUPAC name of glycerol "Propane-1,2,3-triol" rather than simply "Propanetriol"?
QUESTION 9 OF 20
What is the proper IUPAC name of a cyclohexane ring bearing a hydroxyl group at C-1 and a bromine atom at C-3?
QUESTION 10 OF 20
Identify the structural classification of Cyclopent-3-en-1-ol:
QUESTION 11 OF 20
Match List I with List II.
| List I | List II |
|---|---|
| 1. Catechol | a. Benzene-1,3-diol |
| 2. Resorcinol | b. Benzene-1,4-diol |
| 3. Hydroquinone | c. Benzene-1,2-diol |
| 4. Phenol | d. Hydroxybenzene |
QUESTION 12 OF 20
The IUPAC name of a phenol molecule with two methyl substituents placed at both ortho positions relative to the hydroxyl group is:
QUESTION 13 OF 20
The locant unit values corresponding to 'meta' substitution in a disubstituted benzene system are:
QUESTION 14 OF 20
Regarding the structure 2,4,6-Trinitrophenol (Picric acid):
1. It is an extensively substituted phenol.
2. It contains nitro groups at both ortho positions and the para position.
3. It has a nitro group at the meta position.
4. The hydroxyl group is at C-1.
QUESTION 15 OF 20
The common name of C₆H₅O(CH₂)₆CH₃ is:
QUESTION 16 OF 20
According to the alphabetical order rule for common names, what is the common name for the molecule 2-Methoxypropane (CH₃–O–CH(CH₃)₂)?
QUESTION 17 OF 20
What is the IUPAC name of a cyclohexane ring bearing an ethoxy group at C-1 and a nitro group at C-2?
QUESTION 18 OF 20
Arrange the following groups in decreasing priority to serve as the parent chain based on carbon count:
1. Isopentyl (5 carbons)
2. Phenyl (6 carbons)
3. Heptyl (7 carbons)
4. Methyl (1 carbon)
QUESTION 19 OF 20
QUESTION 20 OF 20
Test Complete!
Answer Review
1 When distinguishing common naming structures, what conceptual difference separates an isobutyl group from a sec-butyl group in alcohols?
�� Isobutyl alcohol is 2-methylpropan-1-ol. �� sec-Butyl alcohol is butan-2-ol. �� Primary and secondary classifications differ.
Isobutyl alcohol (2-methylpropan-1-ol) contains a branched carbon skeleton, but the hydroxyl-bearing carbon is attached to only one other carbon atom, making it a primary alcohol. sec-Butyl alcohol (butan-2-ol) has the hydroxyl-bearing carbon attached to two other carbon atoms, making it a secondary alcohol. Therefore, option B is correct.
- �� Option A → Isobutyl is also branched, not linear.
- �� Option C → Incorrect alcohol classifications.
- �� Option D → They are different compounds.
Used
- Elimination
Application:
- Compare the carbon attached directly to the hydroxyl group.
Final Logic:
- Primary branched alcohol vs secondary alcohol.
Iso = Primary, Sec = Secondary
2 Which of the following strictly adhere to the IUPAC rules for naming alcohols?
1. In polyhydric alcohols, the 'e' of alkane is retained and ending 'ol' added.
2. The position of substituents are indicated using numerals determined by proximity to the hydroxyl group.
3. 'Cyclo' is added before the parent chain of any alcohol containing a benzene ring.
4. Multiplicative prefixes do not alter the retention of the 'e' in polyhydric species.
�� Polyhydric alcohols retain the terminal "e". �� OH group gets numbering priority. �� Cyclo is used only for cyclic aliphatic systems.
Statement 1 is correct because names such as ethane-1,2-diol retain the terminal "e". Statement 2 is correct because numbering is based on giving the hydroxyl group the lowest possible locant. Statement 3 is incorrect because benzene-containing compounds are not named using the prefix "cyclo". Statement 4 is correct because the use of diol, triol, etc. retains the "e" of the parent alkane. Therefore, statements 1, 2 and 4 are correct.
- �� Option B → Includes statement 3, which is incorrect.
- �� Option C → Includes statement 3, which is incorrect.
- �� Option D → Omits statements 2 and 4.
Used
- Elimination
Application:
- Check each statement against NCERT nomenclature rules.
Final Logic:
- Statements 1, 2 and 4 are correct; statement 3 is incorrect.
Poly = Keep e
3 What is the IUPAC name of the complex unsaturated alcohol CH₂=CH–CH(OH)–CH₃?
�� OH group receives numbering priority. �� Double bond is also included in the parent chain. �� Alcohol suffix has priority over alkene numbering.
Numbering is carried out from the end nearest to the hydroxyl group. This gives the hydroxyl group locant 2 and the double bond locant 3. Therefore, the correct IUPAC name is But-3-en-2-ol.
- �� Option B → Gives lower priority to OH.
- �� Option C → Uses hydroxy as a prefix instead of the principal suffix.
- �� Option D → Incorrect numbering convention.
Used
- Substitution
Application:
- Assign the lowest possible number to the hydroxyl group.
Final Logic:
- OH priority → But-3-en-2-ol.
OH Before EN
4 Arrange the sequence of the substituent locants in ascending numerical order for the molecule 4-Chloro-3-ethyl-2-(1-methylethyl)-butan-1-ol:
1. Chloro
2. (1-methylethyl)
3. Ethyl
4. Hydroxyl (ol)
�� OH group determines numbering. �� Remaining substituents receive locants accordingly. �� Ascending order follows the assigned positions.
From the name: 4 → Hydroxyl group at carbon 1. 2 → (1-methylethyl) group at carbon 2. 3 → Ethyl group at carbon 3. 1 → Chloro group at carbon 4. Therefore, the ascending locant order is: Hydroxyl (1) < (1-methylethyl) (2) < Ethyl (3) < Chloro (4).
- �� Option B → Assigns incorrect locants.
- �� Option C → Incorrect ordering.
- �� Option D → Gives descending order.
Used
- Option Grouping
Application:
- Read the locants directly from the IUPAC name.
Final Logic:
- 1 < 2 < 3 < 4.
OH Starts the Count
5 In compounds containing both a double bond and a hydroxyl group (e.g., Hex-1-en-3-ol):
1. The alkene gets numbering priority over the hydroxyl group.
2. The hydroxyl group gets numbering priority, dictating the end from which the chain is numbered.
3. The suffix 'en' comes before 'ol' in the final name.
4. The parent chain must contain both the double bond and the hydroxyl carbon.
�� OH has higher priority than C=C. �� Both functional features remain in the parent chain. �� Names contain both "en" and "ol".
Statement 1 is incorrect because the hydroxyl group has higher priority than the double bond. Statement 2 is correct because numbering is chosen to give the hydroxyl group the lowest locant. Statement 3 is correct because names are written in the form en-ol. Statement 4 is correct because the selected parent chain must contain both the double bond and the carbon bearing the hydroxyl group. Therefore, statements 2, 3 and 4 are correct.
- �� Option A → Includes statement 1, which is incorrect.
- �� Option C → Includes statement 1, which is incorrect.
- �� Option D → Omits statement 4.
Used
- Elimination
Application:
- Apply priority rules between hydroxyl and alkene groups.
Final Logic:
- OH > C=C for numbering priority.
OH Wins Over EN
6 Match List I with List II.
| List I | List II |
|---|---|
| 1. 4-Chloro-2,3-dimethylpentan-1-ol | a. A diol with methyls at C-2 and C-5 |
| 2. 2-Ethoxy-1,1-dimethylcyclohexane | b. An ether with a nitro group at C-2 |
| 3. 1-Ethoxy-2-nitrocyclohexane | c. A primary alcohol with chloro at C-4 |
| 4. 2,5-Dimethylhexane-1,3-diol | d. A cyclic ether with gem-dimethyls at C-1 |
�� Names directly describe structural features. �� Functional groups determine classification. �� Locants identify positions precisely.
1 → c : Primary alcohol with chloro at C-4. 2 → d : Cyclohexane containing ethoxy and gem-dimethyl substitution. 3 → b : Ether with a nitro substituent at carbon 2. 4 → a : Diol with methyl groups at carbons 2 and 5. Therefore, option A is correct.
- �� Option B → Multiple mismatches.
- �� Option C → Ether structures incorrectly paired.
- �� Option D → Primary alcohol incorrectly matched.
Used
- Option Grouping
Application:
- Match structural descriptions with their nomenclature.
Final Logic:
- Interpret locants and functional groups directly.
Name → Structure Match
7 The IUPAC name of the heavily substituted diol structure CH₃–CH(CH₃)–CH₂–CH(OH)–CH(CH₃)–CH₂–OH is:
�� Longest chain contains six carbons. �� Two hydroxyl groups are present. �� Lowest locants are assigned to OH groups.
Numbering from the hydroxyl end gives hydroxyl positions 1 and 3 and methyl substituents at positions 2 and 5. Therefore, the correct IUPAC name is 2,5-Dimethylhexane-1,3-diol.
- �� Option A → Improper substituent naming.
- �� Option B → Incorrect hydroxyl numbering.
- �� Option C → Not the preferred NCERT naming style.
Used
- Substitution
Application:
- Assign lowest locants to hydroxyl groups.
Final Logic:
- OH positions = 1,3; methyls = 2,5.
OH First, Then Methyl
8 Why is the formal IUPAC name of glycerol "Propane-1,2,3-triol" rather than simply "Propanetriol"?
�� Polyhydric alcohols require locants. �� Positions of OH groups must be specified. �� Prevents ambiguity.
IUPAC nomenclature requires explicit locants for hydroxyl groups in polyhydric alcohols. The name Propane-1,2,3-triol clearly specifies the locations of all three hydroxyl groups and avoids ambiguity. Therefore, option B is correct.
- �� Option A → Triol does not imply multiple carbon chains.
- �� Option C → Too specific and not the general rule.
- �� Option D → Not the reason for locants.
Used
- Elimination
Application:
- Apply IUPAC rules for naming polyhydric alcohols.
Final Logic:
- Locants ensure unambiguous structure identification.
Polyhydric = Position Required
9 What is the proper IUPAC name of a cyclohexane ring bearing a hydroxyl group at C-1 and a bromine atom at C-3?
�� OH-bearing carbon is C-1. �� Bromine occupies carbon 3. �� Parent compound is cyclohexanol.
In cyclic alcohols, the carbon bearing the hydroxyl group is automatically assigned position 1. Bromine is located at carbon 3. Therefore, the correct name is 3-Bromocyclohexanol.
- �� Option B → Incorrect numbering style.
- �� Option C → Incorrect parent structure.
- �� Option D → Phenol contains a benzene ring.
Used
- Substitution
Application:
- Assign OH-bearing carbon as C-1.
Final Logic:
- Cyclohexanol + Br at C-3.
OH = 1 in Rings
10 Identify the structural classification of Cyclopent-3-en-1-ol:
�� Contains a ring structure. �� Contains a carbon-carbon double bond. �� Hydroxyl-bearing carbon is secondary.
Cyclopent-3-en-1-ol contains a cyclopentane ring with a double bond, making it unsaturated. The carbon bearing the hydroxyl group is attached to two other ring carbons and is therefore secondary. Hence, the compound is classified as an unsaturated cyclic secondary alcohol.
- �� Option A → Compound is unsaturated.
- �� Option C → Not aromatic and contains only one OH group.
- �� Option D → Not an ether.
Used
- Elimination
Application:
- Identify ring type, saturation and alcohol classification.
Final Logic:
- Cyclic + C=C + Secondary OH carbon.
Ring + EN + OH = Unsaturated Alcohol
11 Match List I with List II.
| List I | List II |
|---|---|
| 1. Catechol | a. Benzene-1,3-diol |
| 2. Resorcinol | b. Benzene-1,4-diol |
| 3. Hydroquinone | c. Benzene-1,2-diol |
| 4. Phenol | d. Hydroxybenzene |
�� Catechol is the ortho dihydric phenol. �� Resorcinol is the meta dihydric phenol. �� Hydroquinone is the para dihydric phenol.
1 → c : Catechol = Benzene-1,2-diol. 2 → a : Resorcinol = Benzene-1,3-diol. 3 → b : Hydroquinone = Benzene-1,4-diol. 4 → d : Phenol = Hydroxybenzene. Therefore, option C is correct.
- �� Option A → Catechol and hydroquinone are interchanged.
- �� Option B → All three dihydric phenols are incorrectly matched.
- �� Option D → Resorcinol and hydroquinone are interchanged.
Used
- Option Grouping
Application:
- Match common names of dihydric phenols with their IUPAC names.
Final Logic:
- Cate = 1,2; Res = 1,3; Hydro = 1,4.
Cate-2, Res-3, Hydro-4
12 The IUPAC name of a phenol molecule with two methyl substituents placed at both ortho positions relative to the hydroxyl group is:
�� Hydroxyl-bearing carbon is C-1. �� Ortho positions are C-2 and C-6. �� Two methyl groups occupy these positions.
In phenol, the carbon carrying the hydroxyl group is assigned position 1. The two ortho positions relative to the hydroxyl group are carbons 2 and 6. Therefore, the correct IUPAC name is 2,6-Dimethylphenol.
- �� Option A → Contains one ortho and one para methyl group.
- �� Option B → Not a phenol.
- �� Option C → Represents meta substitution.
Used
- Substitution
Application:
- Assign carbon 1 to OH and identify ortho positions.
Final Logic:
- Ortho to OH = 2 and 6.
OH = 1 → Ortho = 2 & 6
13 The locant unit values corresponding to 'meta' substitution in a disubstituted benzene system are:
�� Meta means one carbon separation. �� Standard aromatic nomenclature. �� Corresponds to 1,3-substitution.
In benzene nomenclature: Ortho = 1,2 Meta = 1,3 Para = 1,4 Therefore, meta substitution corresponds to positions 1 and 3.
- �� Option A → Ortho substitution.
- �� Option C → Para substitution.
- �� Option D → Not represented by meta nomenclature.
Used
- Memory-Based Elimination
Application:
- Recall ortho-meta-para positions.
Final Logic:
- Meta = 1,3.
O = 2, M = 3, P = 4
14 Regarding the structure 2,4,6-Trinitrophenol (Picric acid):
1. It is an extensively substituted phenol.
2. It contains nitro groups at both ortho positions and the para position.
3. It has a nitro group at the meta position.
4. The hydroxyl group is at C-1.
�� Picric acid is 2,4,6-trinitrophenol. �� Nitro groups occupy ortho and para positions. �� OH-bearing carbon is carbon 1.
Statement 1 is correct because picric acid is a highly substituted phenol. Statement 2 is correct because nitro groups are present at positions 2 and 6 (ortho) and position 4 (para). Statement 3 is incorrect because no nitro group is present at a meta position. Statement 4 is correct because numbering starts from the hydroxyl-bearing carbon, which is C-1. Therefore, statements 1, 2 and 4 are correct.
- �� Option B → Includes statement 3, which is incorrect.
- �� Option C → Includes statement 3 and omits statement 1.
- �� Option D → Statement 3 is incorrect.
Used
- Elimination
Application:
- Verify each substituent position from the IUPAC name.
Final Logic:
- 2,4,6 = Ortho, Para, Ortho.
Picric = 2,4,6 Nitro
15 The common name of C₆H₅O(CH₂)₆CH₃ is:
�� Oxygen joins a phenyl group and a heptyl group. �� Common names list groups followed by ether. �� This is a mixed ether.
The ether contains a phenyl group (C₆H₅–) and a heptyl group ((CH₂)₆CH₃). According to common nomenclature, the two groups are written as separate words followed by "ether". Therefore, the common name is heptyl phenyl ether.
- �� Option A → Not the NCERT naming order.
- �� Option C → Contains a benzyl group, not phenyl.
- �� Option D → IUPAC-style nomenclature, not common nomenclature.
Used
- Substitution
Application:
- Identify the groups attached to oxygen.
Final Logic:
- Heptyl + Phenyl + Ether.
Phenyl + Alkyl = Alkyl Phenyl Ether
16 According to the alphabetical order rule for common names, what is the common name for the molecule 2-Methoxypropane (CH₃–O–CH(CH₃)₂)?
�� Ether contains methyl and isopropyl groups. �� Common names use alphabetical order. �� Ether is written at the end.
The molecule contains a methyl group and an isopropyl group attached to oxygen. In common nomenclature, these groups are written as separate words followed by "ether". NCERT lists this compound as methyl isopropyl ether.
- �� Option A → Uses propyl instead of isopropyl.
- �� Option C → Not the convention used in NCERT examples.
- �� Option D → Incorrect structure.
Used
- Elimination
Application:
- Identify the alkyl groups attached to oxygen.
Final Logic:
- Methyl + Isopropyl + Ether.
Me + Iso = Ether
17 What is the IUPAC name of a cyclohexane ring bearing an ethoxy group at C-1 and a nitro group at C-2?
�� Cyclohexane is the parent ring. �� Ethoxy group is at carbon 1. �� Nitro group is at carbon 2.
The parent structure is cyclohexane. The substituents are ethoxy at C-1 and nitro at C-2. Therefore, the correct IUPAC name is 1-Ethoxy-2-nitrocyclohexane.
- �� Option A → Incorrect locant assignment.
- �� Option B → Incorrect numbering sequence.
- �� Option C → Not a valid IUPAC name.
Used
- Substitution
Application:
- Assign substituent positions according to the given structure.
Final Logic:
- Ethoxy at 1, Nitro at 2.
Ethoxy First, Nitro Next
18 Arrange the following groups in decreasing priority to serve as the parent chain based on carbon count:
1. Isopentyl (5 carbons)
2. Phenyl (6 carbons)
3. Heptyl (7 carbons)
4. Methyl (1 carbon)
�� Larger carbon frameworks receive parent priority. �� Carbon count determines the order. �� Heptyl contains the highest carbon count.
Carbon counts are: 3 → Heptyl = 7 carbons 2 → Phenyl = 6 carbons 1 → Isopentyl = 5 carbons 4 → Methyl = 1 carbon Therefore, decreasing priority is: Heptyl > Phenyl > Isopentyl > Methyl.
- �� Option B → Places heptyl after smaller groups.
- �� Option C → Gives increasing order.
- �� Option D → Phenyl should precede isopentyl.
Used
- Option Grouping
Application:
- Arrange groups according to decreasing carbon count.
Final Logic:
- 7C > 6C > 5C > 1C.
H > P > I > M
19
�� The hydroxyl-bearing carbon is C-1. �� The methyl group is on the adjacent carbon. �� The ring contains five carbons.
The parent structure is cyclopentanol. The carbon carrying the hydroxyl group is assigned position 1. The adjacent carbon receives position 2 and bears the methyl substituent. Hence, the correct IUPAC name is 2-Methylcyclopentanol.
- �� Option B → Incorrect numbering convention.
- �� Option C → Different structural arrangement.
- �� Option D → Six-membered ring.
Used
- Contextual/Tonal Matching
Application:
- Apply the cyclic alcohol naming rule from the passage.
Final Logic:
- Cyclopentanol + Methyl at C-2.
OH = 1 in Rings
20
�� Benzene is the larger parent structure. �� Methoxy acts as the substituent. �� Ether is named as an alkoxy derivative.
The larger group is the benzene ring, which becomes the parent hydrocarbon. The smaller group attached through oxygen is the methoxy substituent. Therefore, the correct IUPAC name is Methoxybenzene.
- �� Option A → Incorrect parent-chain selection.
- �� Option C → Not the accepted IUPAC name.
- �� Option D → Not a valid IUPAC name.
Used
- Substitution
Application:
- Select the larger group as parent and convert the smaller group into an alkoxy substituent.
Final Logic:
- Benzene parent + Methoxy substituent = Methoxybenzene.
Anisole = Methoxybenzene
