Overview
This lecture covers the occurrence, classification, chemical properties, and industrial preparation of transition metals and their compounds, focusing on extraction techniques, common oxidation states, and the significance of these metals in technology and daily life.
Classification and Occurrence of Transition Metals
- Transition metals have (or can form) partially filled d orbitals.
- Groups 3–11 contain the d-block (transition) elements; group 12 elements are sometimes included.
- f-block elements (lanthanides, actinides) are called inner transition metals.
- The d-block is split into four series; the f-block consists of lanthanide and actinide series.
- Lanthanum and actinium behave like their respective f-block series.
Electron Configurations and Oxidation States
- For transition/inner transition metals, s electrons are lost before d or f electrons in ionization.
- Transition metals have multiple stable oxidation states, especially near the middle of the series.
- Lighter d-block elements form stable, colorful ions in water; heavier ones often form oxyanions.
- Highest oxidation states are typically more stable in the middle and heavier series of transition metals.
Extraction and Preparation of Transition Metals
- Extraction generally involves: (1) preliminary treatment, (2) smelting, (3) refining.
- Iron is primarily obtained from oxides using blast furnaces and carbon as the reducing agent.
- Copper is usually extracted from sulfide ores via roasting, followed by reduction.
- Silver is separated by hydrometallurgy, using cyanide leaching and reduction by zinc or iron(II).
Properties and Compounds of Transition Metals
- Transition metals are hard, high-melting, good conductors, and form a variety of alloys.
- They readily form cations and coordination compounds.
- Transition metal compounds can be ionic or covalent, depending on oxidation state.
- Common classes: halides, oxides, hydroxides, carbonates, and other salts, each with varied preparation and properties.
Industrial and Everyday Significance
- Lanthanides are not truly rare but are hard to separate; crucial in electronics and energy tech.
- High-temperature superconductors use transition metals and operate at liquid nitrogen temperatures, with potential for widespread application.
Key Terms & Definitions
- Transition Metals — Elements with partially filled d orbitals, mostly in groups 3–11.
- Inner Transition Metals — Lanthanides and actinides (f-block elements).
- Oxidation State — The charge an atom would have if electrons were transferred completely.
- Smelting — Extraction of metal in molten form from ore via reduction.
- Slag — Byproduct formed from impurities during metal extraction.
- Hydrometallurgy — Extraction of metals from ores using aqueous chemistry.
- Coordination Compound — Complex where a metal ion binds to electron-pair donors (ligands).
- Superconductor — Material conducting electricity with zero resistance.
Action Items / Next Steps
- Review electron configurations and practice writing them for transition metal ions.
- Complete exercises on extraction processes for iron, copper, and silver.
- Read upcoming sections on coordination compounds and their chemistry.
- Explore standard reduction potentials to predict redox reactions involving transition metals.