A.H2SO4(aq)+BaCl2(aq)=2HCl(aq)+BaSO4(s) ΔH<0 B.2CH3OH(l)+3O2(g)→2CO2(g)+4H2O(l) ΔH<0 C.4Fe(OH)2(s)+2H2O(l)+O2(g)=4Fe(OH)3(s) ΔH<0 D.3Cu(s)+8HNO3(aq)=3Cu(NO3)2(aq)+2NO(g)+4H2O(l) ΔH<0