1. With the aid of a Hess cycle, determine the enthalpy of the decomposition reaction of sodium nitrate, NaNO3 to sodium nitrite, NaNO2 and oxygen, O2. [5] Enthalpy of formation of NaNO3 = -468 kJ/mol
Enthalpy of formation of NaNO2 = -369kJ/mol

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na