Reactions of Acids with Metal Oxides & Hydroxides
- Metal oxides and metal hydroxides act as bases
- Bases have pH values above 7
- Many bases are insoluble in water but the ones that do dissolve in water are called alkalis
- Examples of alkalis are soluble metal hydroxides such as NaOH and Ca(OH)2
- When bases react with acids, a neutralisation reaction occurs
- In all acid-base neutralisation reactions, salt and water are produced:
acid + base ⟶ salt + water
- This neutralisation reaction can be generalised to the H+ ions (from the acid) reacting with the OH– ions (from the base) to produce water
- The overall ionic equation for this is:
H+ + OH– ⟶ H2O
- The identity of the salt produced depends on the acid used and the positive ions in the base
- Hydrochloric acid produces chlorides, sulfuric acid produces sulfate salts and nitric acid produces nitrates
Acids and Metals Oxides or Hydroxides Summary Table
- The following are some specific examples of reactions between acids and metal oxides / hydroxides:
2HCl + CuO ⟶ CuCl2 + H2O
H2SO4 + 2NaOH ⟶ Na2SO4 + 2H2O
HNO3 + KOH ⟶ KNO3 + H2O