[appleseed]

Hello! I cant seem to work out the question because there doesnt seem to be enough info given! how can i get the enthalpy values from the spontaneity info given ! grrr..
any help would really be appreciated!!
cheers!


QUESTION
consider the following two reactions
2Fe(s) + O2(g)---> 2FeO(s)                       Delta G (standard conditions) : -450kJ/mol at 500K             
2CO (g) +O2 (g)---> 2CO2(g)                      Delta G (standard conditions) : -480kJ/mol at 500K

use hess's law to determine Delta G (at standard condition) for the reaction :
2FeO(s) +2CO(g)---> 2Fe(s) +2CO2(g)

[Vidya]

No need of calculating delta H here
combine both the equations and add up delta G using hess's law.

[UG]

Reverse equation one and then add the two together:

2FeO  O₂ + 2Fe                    +450kJ mol^-1
2CO + O₂  2CO₂                   -480kJ mol^-1

The O₂ will cancel out giving you:

2FeO +2CO  2Fe +2CO₂