which of the following chemical equations is an acid-base reaction?
a) Ba(OH)2(aq) + K2SO4(aq)---> BaSO4(s) + 2 KOH(aq)

b) 3 NaOH(aq) + AlCl3(aq)---> Al(OH)3(s) + 3 NaCl(aq)

c) 2 H+(aq) + Zn(s)---> H2(g) + Zn2+(aq)

d) 2 HCl(aq) + Pb(NO3)2(aq)---> PbCl2(s) + 2 HNO3(aq)

e) H3PO4(aq) + NH3(aq)---> NH4+(aq) + H2PO4-(aq)

in an acid base reaction - check in which reaction we have a base and acid present as the reactants
if the product is formed by transfer of H+ from base to acid or in the product a salt and water is formed