Which reaction does not readily occur at room temperature?
2 HCl + Zn(OH)2 -> ZnCl2 + 2 H2O
Cu2+ (aq) + 4 NH3 -> Cu(NH3)4 2+ (aq)
NH3 + HCl -> NH4Cl
2 HCl -> H2 + Cl2
Given only the given information, how can I tell which one doesn't occur at room temperature? The only thing I could really think of, is perhaps entropy. NH3 + HCl -> NH4Cl does appear to go from 2 molecules to one but so does Cu2+ (aq) + 4 NH3 -> Cu(NH3)4 2+ (aq), here though it is just (aq). Am I at least headed in the right direction? Do I even need to know the different states or more information?