Answer:
-2.86x10³ kJ
Explanation:
The enthalpy of a reaction (ΔH) is defined as the heat produced or consumed by a reaction. In the reaction:
2 C₂H₆(g) + 7 O₂(g) → 4 CO₂(g) + 6 H₂O(g)
The ΔH is the heat envolved in the reaction per 2 moles of C₂H₆. 1.43x10³ kJ are involved when 1 mole reacts. Thus, when 2 moles react, involved heat is:
1.43x10³ kJ ₓ 2 = 2.86x10³ kJ. As the reaction is a combustion reaction (Produce CO₂ and H₂O), the heat involved in the reaction is PRODUCED, that means ΔH is negative, -2.86x10³ kJ