A.Hg(l) B.Na2SO4(s) C.Br2(l) D.H2O(g)
A.442.3kJ•mol-1 B.260.7kJ•mol-1 C.–442.3kJ•mol-1 D.-260.7kJ•mol-1
A.2Ag(s)+Cl2(g)═2AgCl(s) B.Ag(g)+1/2Cl2(g)═AgCl(s) C.Ag(s)+1/2Cl2(g)═AgCl(s) D.Ag+(aq)+Cl-(aq)═AgCl(s)