The heat of comustion of napthalene, `C_(10)H_(8)(S)`, at constant volume at `25^(@)`C was found to be -5133 kJ `mol^(-1)`. Calculate the value of enthalpy change at the same temperature.

Explanation

The combustion reaction of napthalene.
`C_(10)H_(8)(s)+12O_(2)(g)rarr 10CO_(2)(g)+4H_(2)O(l), " " Delta E=-5133 KJ`
`Delta n_(g)=10-12=-2` mol.
Now applying the relation. `Delta H = Delta H+Delta n_(g)RT=-5133xx10^(3)+(-2)(8.314)(298)`
`=-513000J-4955.14 J=-5137955.14` joule.