Overview
This lecture introduces chemical nomenclature, focusing on using flow charts to name inorganic compounds through examples of increasing complexity.
Introduction to Chemical Nomenclature
- Nomenclature means a system for naming things, specifically chemical compounds in this context.
- Chemists need to translate chemical symbols and formulas into proper compound names.
Flow Chart for Naming Inorganic Compounds
- Start at the top of the chart and answer each yes/no question to follow the path.
- Questions help determine if a compound has hydrogen, contains metals with multiple oxidation numbers, or includes polyatomic ions.
Example 1: Metal and Nonmetal (NaCl)
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NaCl does not start with hydrogen.
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Sodium is not a metal with multiple oxidation numbers.
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There is no polyatomic ion present.
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Name the first element: sodium; change second element ending to "ide" for chlorine: chloride.
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Final name: sodium chloride.
Example 2: Metal and Polyatomic Ion (Ca(OH)₂)
- Ca(OH)₂ does not start with hydrogen nor a multivalent metal.
- Contains the polyatomic ion OH⁻ (hydroxide).
- Name first element: calcium; then name the polyatomic ion: hydroxide.
- Final name: calcium hydroxide.
Example 3: Metal with Multiple Oxidation States and Polyatomic Ion (CuNO₃)
- Copper starts the formula and can have multiple oxidation numbers.
- Requires determination of copper’s oxidation state using the charge of the accompanying polyatomic ion (nitrate, NO₃⁻).
- Nitrate has a -1 charge, so copper must be +1, noted as (I).
- Final name: copper(I) nitrate.
d-Block Elements with Multiple Oxidation States
- Many d-block elements (e.g., iron, copper, tin, lead, gold, mercury) commonly have multiple possible charges.
- These elements often require specifying the oxidation number in compound names.
Key Terms & Definitions
- Nomenclature — a systematic method for naming compounds.
- Polyatomic Ion — an ion composed of multiple atoms bonded together, carrying a charge (e.g., OH⁻, NO₃⁻).
- Oxidation Number — the charge an atom would have if electrons were transferred completely.
- d-Block Elements — elements in the center of the periodic table known for forming multiple charges.
Action Items / Next Steps
- Use the provided flow chart while practicing naming chemical compounds.
- Review the list of common polyatomic ions for class.