Nomenclature

Key Notes:

Definition:

• Nomenclature is the system of naming objects, organisms, or chemical compounds systematically to avoid confusion.

Types of Nomenclature:

Biological Nomenclature:

• Governed by the International Code of Nomenclature (ICN).
• Binomial nomenclature assigns each organism a two-part Latin name (Genus and species).
• Example: Homo sapiens (Human).

Chemical Nomenclature:

• Governed by the International Union of Pure and Applied Chemistry (IUPAC).
• Systematic naming of chemical compounds ensures clear communication globally.

Binomial Nomenclature:

Introduced by Carl Linnaeus.

Rules:

• The genus name is capitalized; the species name is lowercase.
• Both names are italicized or underlined when handwritten.

IUPAC Nomenclature in Chemistry:

Used to name organic and inorganic compounds.

Rules for Organic Compounds:

• Identify the longest continuous chain of carbon atoms.
• Assign the root name based on the number of carbons (e.g., meth-, eth-, prop-).
• Use prefixes for substituents and suffixes for functional groups (e.g., -ane, -ene, -yne).

Rules for Inorganic Compounds:

• Name cations (positive ions) first, followed by anions (negative ions).
• Use Roman numerals to indicate oxidation states if necessary (e.g., Iron (III) chloride).
• Prefixes indicate the number of atoms in covalent compounds (e.g., carbon dioxide, CO₂).

Importance of Nomenclature:

• Provides a universal language for scientists and students.
• Eliminates ambiguity in identifying organisms or substances.
• Facilitates communication across disciplines and countries.

Examples:

• Biological: Panthera leo (Lion), Zea mays (Maize).
• Chemical: H₂O (Water), NaCl (Sodium chloride), CH₄ (Methane).

Let’s practice!