Nomenclature IUPAC Rules - UNSOLVED PRACTICE SET
Chapter: Organic Chemistry Basic Principles | Topic: Nomenclature IUPAC Rules
NOMENCLATURE IUPAC RULES - UNSOLVED PRACTICE SET
Topic: Nomenclature IUPAC Rules
Multiple Choice Questions
Q1. The IUPAC name of CH₃–CH₂–CH₂–CH₃ is:
- Butane
- Isobutane
- n-Butane
- 1-Butene
Q2. In IUPAC nomenclature, the longest continuous carbon chain is called the:
- Parent chain
- Side chain
- Functional group
- Substituent
Q3. The IUPAC name of CH₃–CH=CH–CH₃ is:
- 1-Butene
- 2-Butene
- But-1-ene
- But-2-ene
Q4. The prefix used for a –CH₃ substituent is:
- Ethyl
- Methyl
- Propyl
- Butyl
Q5. The correct IUPAC name of the compound with structure:
plain
CH₃
|
CH₃–C–CH₂–CH₃
|
CH₃
is:
- 2,2-Dimethylbutane
- 3,3-Dimethylbutane
- 2-Ethyl-2-methylpropane
- Neopentane
Q6. The IUPAC name of CH₃–CH(OH)–CH₃ is:
- 1-Propanol
- 2-Propanol
- Propan-1-ol
- Propan-2-ol
Short Answer Questions
Q7. Write the IUPAC names of the following compounds:
(a) CH₃–CH₂–CH₂–CH₂–OH
(b) CH₃–CO–CH₃
(c) CH₃–CH₂–CHO
(d) CH₃–CH₂–COOH
Q8. Draw the structures of:
(a) 2-Methylbutane
(b) 3-Ethyl-2-methylpentane
(c) Cyclohexene
(d) 2-Chloropropanoic acid
Q9. Explain the difference between a primary (1°), secondary (2°), and tertiary (3°) carbon atom with examples.
Q10. Write the IUPAC names of the following compounds:
(a) CH₃–CH(Br)–CH₂–CH₃
(b) CH₂=CH–CH₂–CH₃
(c) CH≡C–CH₂–CH₃
(d) CH₃–O–CH₂–CH₃
Q11. Your chemistry teacher asks you to name a compound found in vanilla flavouring with the formula C₈H₈O₃ containing a –CHO group and a –OH group on a benzene ring. Write its IUPAC name and common name.
Q12. What is the difference between a common name and an IUPAC name? Why is the IUPAC system preferred over common names?
Long Answer Questions
Q13. Explain the rules of IUPAC nomenclature for naming alkanes, alkenes, and alkynes. Include:
(a) Selection of the parent chain
(b) Numbering of the carbon chain
(c) Naming and locating substituents
(d) Indicating the position of multiple bonds
Illustrate each rule with a suitable example.
Q14. Discuss the IUPAC nomenclature of compounds containing functional groups. For each of the following, explain the rules and give one example:
(a) Alcohols (suffix: -ol)
(b) Aldehydes (suffix: -al)
(c) Ketones (suffix: -one)
(d) Carboxylic acids (suffix: -oic acid)
(e) Ethers (prefix: alkoxy)
Q15. Naming organic compounds correctly is crucial in chemistry, medicine, and industry. Discuss:
(a) Why a single compound can have multiple common names but only one IUPAC name
(b) How incorrect nomenclature can lead to dangerous mistakes in pharmaceutical manufacturing
(c) The importance of IUPAC naming in India's chemical industry and export documentation
Numerical / Application-Based Problems
Q16. A compound has the molecular formula C₆H₁₂.
(a) How many structural isomers (including stereoisomers) are possible for this formula? List them with their IUPAC names.
(b) Identify which of these isomers would show geometrical isomerism.
(c) Draw the structures of cis and trans isomers if they exist.
Q17. Write the IUPAC names for the following complex structures:
(a) A six-carbon chain with methyl groups at positions 2 and 4, and a double bond at position 1
(b) A five-carbon chain with an ethyl group at position 3, a chlorine at position 2, and a triple bond at position 1
(c) A benzene ring with –OH at position 1, –NO₂ at position 3, and –CH₃ at position 5
(d) Draw the structure of each compound named above.
Q18. A pharmaceutical company in Hyderabad is manufacturing a drug with the structure:
plain
COOH
|
CH₃–C–CH₂–CH₃
|
NH₂
(a) Write the correct IUPAC name of this compound.
(b) If the company mistakenly labels it with a wrong name, what legal and safety consequences could arise?
(c) A student draws the structure of 3-methyl-2-pentanone. Draw its structure and verify if the name is correct according to IUPAC rules.