Final answer:
The reaction that would have an enthalpy change equal to ΔHfo is Fe(s) + 3/2 Cl2(g) FeCl3(s).
Step-by-step explanation:
The reaction that would have an enthalpy change equal to ΔHfo is Fe(s) + 3/2 Cl2(g) → FeCl3(s). In this reaction, one mole of iron reacts with 3/2 moles of chlorine gas to produce one mole of FeCl3. The enthalpy change for this reaction is equal to the standard enthalpy of formation of FeCl3.