At 25^(@)C, the combustion of 1 mol of liquid benzene, the heat of reaction at constant pressure is given by C_(6)H_(6)(l) + 7/2O_(2)(g) to 6 CO_(2)(g) + 3H_(2)O(l) Delta H = -780.980 cal Calculate the heat of reaction at constant volume.

At 25^(@)C, the combustion of 1 mol of liquid benzene, the heat of rea

1.	At 25^(@)C, the combustion of 1 mol of liquid benzene, the heat of reaction at constant pressure is given by C_(6)H_(6)(l) + 7/2O_(2)(g) to 6 CO_(2)(g) + 3H_(2)O(l) Delta H = -780.980 cal Calculate the heat of reaction at constant volume.
Answer» 780.086kcal `-782.470` kcal `-390.043` kcal 390.043 kcal Solution :`DELTAH = DELTAU + Deltan_(g) RT` `Deltan_(g) = 6-7/2 = 2.5` `DeltaU = DeltaH - Deltan_(g)RT` ` = -780980 -(2.5) xx 2 xx 298` ` = -782470` CAL or = -782.470 kcal