The standard molar heat of formation of ethane, C O 2 and water are respectively - 21.1, - 94.1 and − 68.3 kcal . The standard molar heat of combustion of ethane will be:

Step-by-step solution

Given, 2C   +   3H 2 → C 2 H 6 ;    ΔH   =   − 21 .1 C + O 2 → CO 2 ; ΔH = − 94.1 H 2 + 1 2 O 2 → H 2 O ; ΔH = − 68.3 Eqs. 2 × (ii) + 3 × (iii) − (i) C 2 H 6 + 7 2 O 2 → 2 C O 2 + 3 H 2 O Δx = 2 − 94.1 + 3 − 68.3 − − 21.1 = − 372 kcal/mol