Describe the methods of preparation of acids and bases with the help of examples.

Explanation

Methods of preparation of acids and bases
Acids
From non-metals: Non-metallic elements on heating with oxygen give corresponding oxides. Some oxides on dissolution in water give the corresponding acids and hence such non-metallic oxides are called acidic oxides.
Eamples: `C + O_(2) rarr CO_(2)`
`" "CO_(2) + H_(2)O rarr H_(2)CO_(3)`
`" "S + O_(2) rarr SO_(2)`
`" "SO_(2) + H_(2)O rarr H_(2)SO_(3)`
`" "2SO_(2) + O_(2) rarr 2SO_(3)`
`" "SO_(3) + H_(2)O rarr H_(2)SO_(4)`
The oxides which are insoluble in water are called neutral oxides.
Examples: NO, CO
Bases
From metals: Metals on heation with oxygen give metal oxides which are basic in nature. These metal oxides on dissolution in water give corresponding alkalies (water soluble base).
Examples: `4Na + O_(2) rarr 2Na_(2)O`
`" "Na_(2)O + H_(2)O rarr 2NaOH`
`" "2Mg + O_(2) rarr 2MgO`,
`" "MgO + H_(2)O rarr Mg(OH)_(2)`