analytical-methods

# Analytical Methods Analytical chemistry answers two questions: "What is it?" (qualitative analysis) and "How much is there?" (quantitative analysis). The methods range from classical wet chemistry — gravimetry, titration, and separation — to instrumental techniques that exploit the interaction of matter with electromagnetic radiation, electric fields, and crystal lattices. This skill covers the major techniques with worked examples of data interpretation. **Agent affinity:** hodgkin (analytical/structural chemistry, primary) **Concept IDs:** chem-mixtures-pure-substances, chem-physical-chemical-properties, chem-density ## Mixtures vs. Pure Substances Understanding what you are analyzing starts with classification: | Category | Subcategory | Characteristics | Example | |---|---|---|---| | Pure substance | Element | Cannot be decomposed further | Gold (Au), oxygen (O2) | | Pure substance | Compound | Fixed composition, decomposable | Water (H2O), NaCl | | Mixture | Homogeneous (solution) | Uniform composition, single phase | Saltwater, air, brass | | Mixture | Heterogeneous | Non-uniform, multiple phases | Granite, oil-and-water | Analytical methods separate mixtures into components and identify/quantify each. ## Physical and Chemical Properties in Analysis **Physical properties** are observed without changing composition: density, melting point, boiling point, color, refractive index, solubility. These are the basis of physical methods of separation and identificati...