a. Classify following oxides as neutral, acidic, basic or amphoteric: `CO,B_(2)O_(3),SiO_(2),CO_(2),Al_(2)O_(3),PbO_(2),Tl_(2)O_(3)`.
b. Write suitable chemical reaction to show their nature.

Explanation

(1) CO = Neutral
(2) `B_(2)O_(3)` = Acidic
Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium metaborate.
`B_(2)O_(3)+2NaOHrarr2NaBO_(2)+H_(2)O`
(3) `SiO_(2)` = Acidic
Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium silicate.
`SiO_(2)+2NaOHrarr2Na_(2)SiO_(3)+H_(2)O`
(4) `CO_(2)` = Acidic
Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium carbonate.
`CO_(2)+2NaOHrarrNa_(2)CO_(3)+H_(2)O`
(5) `Al_(2)O_(3)` = Amphoteric
Amphoteric substances react with both acids and bases. `Al_(2)O_(3)` reacts with both NaOH and `H_(2)SO_(4)`.
`Al_(2)O_(3)+2NaOHrarrNaAlO_(2)`
`Al_(2)O_(3)+3H_(2)SO_(4)rarrAl_(2)(SO_(4))_(3)+3H_(2)O`
(6) `PbO_(2)` = Amphoteric
Amphoteric substances react with both acids and bases. `PbO_(2)` reacts with both NaOH and `H_(2)SO_(4)`.
`PbO_(2)+2NaOHrarrNa_(2)PbO_(3)+H_(2)O`
`2PbO_(2)+2H_(2)SO_(4)rarr2PbSO_(4)+2H_(2)O+O_(2)`
(7) `Tl_(2)O_(3)` = Basic
Being basic, it reacts with acids to form salts. It reacts with HCl to form thallium chloride.
`Tl_(2)O_(3)+6HClrarr2TlCl_(3)+3H_(2)O`