Răspuns:
MgO+2HBr=MgBr2+H2O
H2CO3 +2KOH =K2CO3+H2O
H2SO4 +Ca(OH)2=CaSO4 +2H2O
Al2O3 +6HCl =2AlCl3+3H2O
2HCl+Mg(OH)2=MgCl2 +2H2O