The heat of reaction for the process described in (a) can be determined by applying Hess's law. The heats of reaction shown in the table below can be obtained experimentally or looked up in tables of enthalpy data. Which two of these heats of reaction would be the easiest and safest to measure in the laboratory, and which two are better obtained through reference sources? Why?
Hint: Consider whether a reaction takes place in aqueous solution or instead involves noxious
gases.
Reaction
NH3(g) --> NH3(aq)
NH3(aq)+ HCI(aq)—> NH4+(aq)+Cl-(aq)
HCI(g)—>HCI(aq)
NH4Cl(s)—>NH4+(aq)+Cl-(aq)
Heat of reaction
AH=-36.64 kJ/mol
AH=-51.6 kJ/mol
AH=-75.14 kJ/mol
AH=+14.8 kJ/mol