Understanding the Concepts
* Oxides: Metal oxides are generally basic, while non-metal oxides are generally acidic.
* Basic Solutions: Basic solutions have a pH greater than 7.
* Reactions with Water: Many metal oxides react with water to form metal hydroxides, which are bases.
The Reaction
The metal oxide MO reacts with water (H₂O) to form the metal hydroxide M(OH):
MO + H₂O → M(OH)₂
Why the Solution is Basic
Metal hydroxides (like M(OH)₂) dissociate in water to produce hydroxide ions (OH⁻):
M(OH)₂ → M²⁺ + 2OH⁻
The presence of hydroxide ions (OH⁻) in the solution makes it basic.
Conclusion
When the oxide MO dissolves in water, it forms a metal hydroxide, which in turn releases hydroxide ions into the solution. This excess of hydroxide ions makes the solution basic.
