(a) Classify following oxides as neutral, acidic, basic or amphoteric:
CO,B2O3,SiO2,CO2,Al2O3,PbO2,Tl2O3
(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+2NaOH→2NaBO2+H2O
(3) SiO2 = Acidic
Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium silicate.
SiO2+2NaOH→2NA2Sio3+H2O
(4) CO2 = Acidic Being acidic, it reacts with bases to form salts. It reacts with NaOH to form sodium carbonate.
CO2+2NaOH→Na2CO3+H2O
(5) Al2O3 = Amphoteric Amphoteric substances react with both acids and bases. Al2O3 reacts with both NaOH and H2SO4.
Al2O3+2NaOH→NaAlO2 + H2O
Al2O3+3H2SO4→Al2(SO4)3 + 3H2O
(6) PbO2 = Amphoteric Amphoteric substances react with both acids and bases. PbO2 reacts with both NaOH and H2SO4.
PbO2+2NaOH→Na2PbO2+H2O
2PbO2+2H2SO4→2PbSO4+2H2O+O2
(7) Tl2O3 = Basic
Being basic, it reacts with acids to form salts. It reacts with HCl to form thallium chloride.
Tl2O3+6HCl→2TlCl3+3H2O