(a)Classify following oxides as neutral, acidic, basic or amphoteric:

CO, B2O3,SiO2, AI2O3,PbO2,TI2O3

(b)Write suitable chemical equations to show their nature.


(1) CO = Neutral

(2) B2O3 = Acidic
Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium
metaborate.

B2O3+2NaOH2NaBO2+H2O

(3) SiO2 = Acidic
Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium silicate.

SiO2+2NaOH2Na2SiO3+H2O

(4) CO2 = Acidic
Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium
carbonate.

CO2+2NaOHNa2CO3+H2O

(5) AI2O3 = Amphoteric
Amphoteric substances react with both acids and bases. Al2O3 reacts with both NaOH
and H2SO4.

AI2O3+2NaOHNaAIO2AI2O3+3H2SO4AI2(SO4)3+3H2O

(6) PbO2 = Amphoteric
Amphoteric substances react with both acids and bases. PbO2 reacts with both NaOH and
H2SO4.

PbO2+2NaOHNa2PbO3+H2O2PbO2+2H2SO42PbSO4+2H2O+O2

(7) TI2O3 = Basic Being basic, it reacts with acids to form salts. It reacts with HCl to form thallium chloride.

TI2O3+6HCI2TICI3+3H2O