The heat of reaction for, `C_(10)H_(8)+12O_(2(g)) rarr 10CO_(2(g))+4H_(2)O_((l))` at constant volume is `-1228.2 kcal` at `25^(@)C`. Calculate the heat of reaction at constant pressure at `25^(@)C`.

Options

A. `-1228.2` kcal
B. `-1229.3 ` kcal
C. `-1232.9` kcal
D. `-1242.6` kcal

Answer

A

Explanation

`C_(18) H_(18) (s) +12O_(2) (g) rarr 10CO_(2) (g) + 4 H_(2) O(l)`
We known that `Delta H= Delta E + Delta ng RT`
`Delta ng=10-12 =-2`
`Delta H = -1228.2xx 10^(3) + (-2) xx 2xx298`
= - 1229393 Ca
= - 1229.39 kcal