Discussion Forum



1)

 Which two sets  of reactants best represents the amphoteric character of Zn(OH)2 ?

Set I:  $Zn(OH)_{2}(s)$ and $OH(aq)$

Set II: $Zn(OH)_{2}(s)$ and $H_{2}O(l)$

Set III:   $Zn(OH)_{2}(s)$ and $H^{+}(aq)$

Set IV:   $Zn(OH)_{2}(s)$ and $NH_{3}(aq)$


A) III and II

B) I and III

C) IV and I

D) II and IV

Answer:

Option B

Explanation:

$Zn(OH)_{2}+ 2O^{-}H\rightarrow ZnO_{2}^{2-}+2H_{2}O$

  Acid     Base                    Salt           water

$Zn(OH)_{2}+ 2H^{+} \rightarrow Zn^{2+}+2H_{2}O$

 Base         Acid                  Salt          water

 The amphoteric character of Zn (OH)2 is represented by I and III