Answer:
455 Kcal
Step-by-step explanation:
2Cl2(g) + 7O2(g) + 130kcal → 2Cl2O7(g)
Rearranging we get,
2Cl2(g) + 7O2(g) → 2Cl2O7(g) Δ H = 130 kcal . mol⁻¹
So for per mol reaction will be as above.
In case of 7 mols of product, we need 7/2 mole ratio x 130 = 455 Kcal