Chemical Thermodynamics Question 198
Question: The heat of combustion of carbon is -94 kcal at 1 atm pressure. The intrinsic energy of $ CO_2 $ is
Options:
A) $ +94,kcal $
B) $ -,94,kcal $
C) $ +47,kcal $
D) $ -47,kcal $
Show Answer
Answer:
Correct Answer: B
Solution:
$ {C _{(S)}}+O_2 {(g)}\to CO_2 {(g)} $ , $ \Delta n _{g}=1-1=0 $
$ \therefore \Delta E=\Delta H=-94kcal $
$ \Delta E={E _{CO_2}}-(E _{C}+{E _{O_2}}) $
$ ={E _{CO_2}}-(0+0) $ or $ {E _{CO_2}}=\Delta E=-94kcal. $
