S8 (rhombic) + 12 O2 (g)-----> 8 SO3 (g) + 752.0 kcal

Question

In the reaction above equated, performed at 25 °c and 1 atm, the formation enthalpy of the SO3 (g) is equal to:

a) +752,0 kcal
b) -752,0 kcal
c) +773,0 kcal
d) -94,0 kcal
e) +94,0 kcal

Answer 1

The reaction is exothermic of 752.0 kJ so dHf = -752.0 kJ/8 mols SO3 or -752.0/8 kJ/mol SO3

Answer 2

thank u :)