问答题
试判断下列反应的ΔrSθm是大于零还是小于零: (1)Zn(s)+2HCl(aq)→ZnCl(aq)+H2(g) (2)CaCO3(s)→CaO(s)+CO2(g) (3)NH3(g)+HCl(g)→NH4Cl(s) (4)CuO(s)+H2(g)→Cu(s)+H2O(l)