Question

Which of the following set contains oxide in the sequence, basic, amphoteric and acidic respectively?

• A. $S{O}_2,P_2{O}_5,CO$
• B. $BaO,A{l}_2{O}_3,Si{O}_2$
• C. $CaO,Si{O}_2,A{l}_2{O}_3$
• D. $A{l}_2{O}_3.C{O}_2,CO$

Answer 1

Answer: (B)

$BaO,A{l}_2{O}_3,Si{O}_2$

Generally Group 1 and Group 2 elements form bases called base anhydrides or basic oxides. Basic oxides are the oxides of metals. If soluble in water, they react with water to produce hydroxides. These metallic oxides are known as basic anhydrides. They react with acids to produce salts

E.g.-$BaO$

Acidic oxides are the oxides of non-metals (Groups 14-17) and these acid anhydrides form acids with water.

$Si{O}_2$

An amphoteric solution is a substance that can chemically react as either acid or base. For example, when $HS{O}_4^{-}$ reacts with water it will make both hydroxide and hydronium ions:

$A{l}_2{O}_3$