Advanced Inorganic Classes and Halogens
Composition, acid-base behavior, redox ability, and ionic equilibria connect the major inorganic classes.
1. Oxide classification
Basic oxides, often metal oxides in lower oxidation states, react with acids to form salt and water. Acidic oxides, often nonmetal oxides in higher oxidation states, react with bases. Amphoteric oxides such as $Al_2O_3$ and $ZnO$ react with both acids and sufficiently strong bases. Neutral oxides such as CO show neither typical acid nor base behavior. Classification is based on reactions, not simply on whether the oxide contains a metal.
Brønsted acids donate $H^+$ and bases accept $H^+$. Lewis acids accept an electron pair and Lewis bases donate an electron pair. The Lewis model explains reactions without proton transfer, including complex formation.
2. Salts, solubility, and hydrolysis
Neutralization combines acid and base, often giving salt and water. In aqueous solution, soluble salts dissociate into ions. Spectator ions cancel from a complete ionic equation. Precipitation occurs when an ion product exceeds the solubility limit. Salt ions can also hydrolyze water: a conjugate acid of a weak base makes solution acidic, while a conjugate base of a weak acid makes it basic. Ions derived from a strong acid and strong base are usually nearly neutral.
- Identify the parent acid and parent base of each ion.