Final answer:
The standard enthalpy change for the reaction N₂(g) + O₂(g) → 2NO(g) is -47.7 kJ.
Step-by-step explanation:
The standard enthalpy change of a reaction can be calculated using the enthalpy changes of the individual reactions involved.
In this case, we have the reactions:
N₂(g) + 2O₂(g) → 2NO₂(g) ΔH = +66.4 kJ
2NO(g) + O₂(g) → 2NO₂(g) ΔH = -114.1 kJ
By adding these two reactions, we can cancel out the common species (NO₂) and obtain the desired reaction:
N₂(g) + O₂(g) → 2NO(g) ΔH = ?
Adding the enthalpy changes, we get a value of +66.4 kJ - 114.1 kJ = -47.7 kJ
Therefore, the standard enthalpy change for the reaction N₂(g) + O₂(g) → 2NO(g) is -47.7 kJ.