Answer:
The forward reaction is an exothermic reaction.
Explanation:
An exothermic reaction is one in which energy is released, usually in the form of heat hence the enthalpy of the reaction is negative. When a reaction exothermic, the energy of the reactants is greater than the energy of the products hence the excess energy is given out as heat. The reactants lie at a higher energy level in the reaction profile compared to the products.
When we look at the reaction given in the question, NO(g) ⇌ 12N2(g) + 12O2(g) ΔH = −90.3 kJ , we can easily see from the thermochemical reaction that the forward reaction is exothermic, energy is released by the reaction system as evidenced by the negative enthalpy of reaction.
