Question

In the following sets of reactants which two sets best exhibit the amphoteric character of $A{l}_2{O}_3.x{H}_{2}O$?
Set 1 : $A{l}_2{O}_3.x{H}_{2}O(s)$ and $O{H}^{-}(aq)$
Set 2 : $A{l}_2{O}_3.,x{H}_{2}O(s)$ and $H_{2}O(l)$
Set 3 : $A{l}_2{O}_3.x{H}_{2}O(s)$ and $H^{+}(aq)$
Set 4 : $A{l}_2{O}_3.,x{H}_{2}O(s)$ and $N{H}_3(aq)$

• A. 1 and 2
• B. 1 and 3
• C. 2 and 4
• D. 3 and 4

Answer 1

Answer: (B)

ln set 1 : $Al{\left(OH\right)}_4^{-}$ is formed

ln set 2 : $A{l}^{+3}\&H_{2}O$ is formed