Answer
See answer below.
Work Step by Step
a) Balanced equation $(NH_4)_2CO_3(aq)+Cu(NO_3)_2(aq)\rightarrow CuCO_3(s)+2\ NH_4NO_3(aq)$
Net ionic equation
$CO_3^{2-}(aq)+Cu^{2+}(aq)\rightarrow CuCO_3(s)$
b) Balanced equation
$Pb(OH)_2(s)+2\ HCl(aq)\rightarrow PbCl_2(s)+2\ H_2O(l)$
Net ionic equation (no spectator ion)
$Pb(OH)_2(s)+2\ H_3O^+(aq)+2\ Cl^-\rightarrow PbCl_2(s)+4\ H_2O(l)$
c) Balanced equation
$BaCO_3(s)+2\ HCl(aq)\rightarrow BaCl_2(aq)+H_2O(l)+CO_2(g)$
Net ionic equation ($Cl^-$ is the only spectator ion)
$BaCO_3(s)+2\ H_3O^+(aq)\rightarrow Ba^{2+}(aq)+3\ H_2O(l)+CO_2(g)$
d)Balanced equation
$2\ CH_3CO_2H(aq)+ Ni(OH)_2(s) \rightarrow Ni(CH_3CO_2)(aq)+2\ H_2O(l)$
Net ionic equation (acetate is the only spectator ion)
$Ni(OH)_2(s)+2\ H_3O^+(aq)\rightarrow Ni^{2+}(aq)+4\ H_2O(l)$
