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NO(g)+1/2O2(g)→NO2(g)
Amphoteric Oxides
Amphoteric oxides are unique oxides that can react with both acids and bases, forming salt and
water in each case. This dual behavior makes them versatile in chemical reactions. Zinc oxide (ZnO)
and lead(II) oxide (PbO) are common amphoteric oxides.
Example: Zinc Oxide (ZnO)
Reaction with Acid:
ZnO(s)+2HCl(aq)→ZnCl2(aq)+H2O(l)
Reaction with Base:
ZnO(s)+2NaOH(aq)+H2O(l)→Na2ZnO2(aq)+H2O(l)
Example Reactions of Lead(II) Oxide (PbO):
As a base with an acid
PbO + 2HCl → PbCl₂ + H₂O
As an acid with a base
PbO + 2NaOH → Na₂PbO₂ + H₂O
Salts
A salt is a compound formed when the hydrogen ion (H⁺) in an acid is replaced by a metal ion. For
example, if we replace the hydrogen in hydrochloric acid (HCl) with a sodium atom, the salt
sodium chloride (NaCl) is produced.
Salts play an essential role in various applications, including fertilizers, batteries, cleaning agents,
healthcare, and fungicides.
Naming Salts
Salts are named based on the reactants involved:
1. First Part – Derived from the metal, metal oxide, or metal carbonate that reacts.
2. Second Part – Based on the acid used in the reaction.
Examples:
- Sodium hydroxide + hydrochloric acid → Sodium chloride
- Zinc oxide + sulfuric acid → Zinc sulfate
Acid naming conventions: