Answer
See answer below.
Work Step by Step
a)$AgNO_3(aq)+KI(aq)\rightarrow AgI(s)+KNO_3(aq)$
Net ionic: $Ag^+(aq)+I^-(aq)\rightarrow AgI(s)$
b)$Ba(OH)_2(aq)+2\ HNO_3(aq)\rightarrow Ba(NO_3)_2(aq)+2\ H_2O(l)$
Net ionic: $2\ H_3O^+(aq)+2\ OH^-(aq)\rightarrow 4\ H_2O(l)$
c) $2\ Na_3PO_4(aq)+3\ Ni(NO_3)_2 (aq)\rightarrow Ni_3(PO_4)_2(s)+6\ NaNO_3(aq)$
Net ionic: $2\ PO_4^{3-}(aq)+3\ Ni^{2+}(aq)\rightarrow Ni_3(PO_4)_2(s)$
