A.Hg(l) B.Na2SO4(s) C.Br2(l) D.H2O(g)
A.-789.3kJ•mol-1 B.0kJ•mol-1 C.+1.9kJ•mol-1 D.-1.9kJ•mol-1
A.442.3kJ•mol-1 B.260.7kJ•mol-1 C.–442.3kJ•mol-1 D.-260.7kJ•mol-1
A.178161 B.-178-161 C.178-161 D.-178161