Using hess's law, what is îhâ°rxn for the following reaction? no(g) + o(g) â no2(g)no(g) + o3(g) â no2(g) + o2(g) îhâ°rxn = â198.8 kj/molo3(g) â 3/2 o2(g) îhâ°rxn= â142.2 kj/molo2(g) â 2o(g) îhâ°rxn= +498.8 kj/mol

The enthalpy of the reaction asked is -306 kJ/mol.

Explanation:

..[1]

..[2]

..[3]

..[4]

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

[1] - [2]  - [3] × 0.5 = [4]

(By using Hess's law)

The enthalpy of the reaction asked is -306 kJ/mol.

i'm assuming that the correct answer is indeed the first one/ "a"..