IUPAC Nomenclature

IUPAC Nomenclature is the standard system of naming chemical compounds as per the International Union of Pure and Applied Chemistry (IUPAC). It ensures a universal language among chemists worldwide.

Table of Contents

• Why Nomenclature is Important?
• Basic Components
• Rules of Naming
• Examples
• Functional Group Suffix Table
• Mnemonic Tips
• Quiz & Practice
• FAQs

Why Is Nomenclature Important?

• Provides unique identification of compounds.
• Ensures global understanding of molecular structures.
• Helps in interpreting chemical reactions correctly.

Basic Components of IUPAC Naming

A systematic name has:

• Prefix – side chains/substituents
• Word Root – number of carbon atoms
• Primary Suffix – saturation/unsaturation (-ane, -ene, -yne)
• Secondary Suffix – functional groups (-ol, -al, -oic acid)

Rules for IUPAC Naming

1. Find the longest carbon chain (parent chain).
2. Number carbons from nearest functional group.
3. Name substituents as prefixes.
4. Assign locants (position numbers).
5. Combine prefix + root + suffix.

Examples

• CH₄ → Methane
• CH₃CH₂CH₃ → Propane
• CH₃CH=CH₂ → Prop-1-ene
• CH₃CH(OH)CH₃ → Propan-2-ol
• CH₃COOH → Ethanoic acid

Functional Group Suffix Table

Functional Group	Formula	Suffix	Example
Alcohol	-OH	-ol	Ethanol
Aldehyde	-CHO	-al	Ethanal
Ketone	>C=O	-one	Propanone
Carboxylic Acid	-COOH	-oic acid	Ethanoic acid

Mnemonic Tips

Carbon chain roots: Meth, Eth, Prop, But, Pent, Hex, Hept, Oct, Non, Dec.

Quiz & Practice

MCQs

1. The IUPAC name of CH₃CH₂OH is:
   A) Methanol
   B) Ethanol ✅
   C) Propanol
   D) Butanol
2. The suffix “-oic acid” represents:
   A) Alcohol
   B) Ketone
   C) Carboxylic acid ✅
   D) Aldehyde

Fill in the Blanks

1. CH₃CHO is called ________. (Answer: Ethanal)

2. The root word for 6 carbons is ________. (Answer: Hex-)

True/False

1. The root “But-” represents 5 carbons. ❌ (False, it’s 4 carbons)

2. Ketones use the suffix “-one”. ✅ (True)

Matching

Compound	Suffix
Alcohol	-ol
Aldehyde	-al
Ketone	-one
Carboxylic acid	-oic acid

FAQs

Q1: What is IUPAC nomenclature?
Ans: It is the universal system of naming chemical compounds developed by IUPAC.

Q2: Why is it important?
Ans: It avoids confusion and ensures international clarity in chemistry.

Q3: What is the root name for 7 carbons?
Ans: Hept-

हिंदी अनुभाग

IUPAC नामकरण रसायनों को नाम देने की एक वैज्ञानिक प्रणाली है। यह वैश्विक स्तर पर एकरूपता बनाए रखती है।

• उदाहरण: CH₄ = मीथेन
• CH₃CH₂OH = एथेनॉल