Answer
See answer below.
Work Step by Step
a)$Ca(OH)_2(aq)+2\ HBr(aq)\rightarrow 2\ H_2O(l)+CaBr_2(aq)$
b)$MgCO_3(aq)+2\ HNO_3(aq)\rightarrow H_2O(l)+CO_3(g)+Mg(NO_3)_2(aq)$
c) $Na_2SO_4(aq)+BaCl_2\rightarrow 2\ NaCl(aq)+BaSO_4(s)$
d)$NH_3(aq)+H_2O(l)\rightarrow NH_4^+(aq)+OH^-(aq)$