The chemical reaction that causes iron to rust in air is given by 4Fe+3O2?2Fe2O3
ID: 704153 • Letter: T
Question
The chemical reaction that causes iron to rust in air is given by
4Fe+3O2?2Fe2O3
in which
=?543.7 J/K
1. What is the Gibbs free energy for this reaction at 3200 K? Assume that ?H and ?S do not change with temperature.
2. At what temperature Teq do the forward and reverse rusting reactions occur in equilibrium?
?Hrxn? =?1648.4 kJ ?Srxn?=?543.7 J/K
1. What is the Gibbs free energy for this reaction at 3200 K? Assume that ?H and ?S do not change with temperature.
2. At what temperature Teq do the forward and reverse rusting reactions occur in equilibrium?
Explanation / Answer
As we know that Delta Grxn =Delta Hrxn - T Delta Srxn
= - 1648.4 x1000-(-543.7x3200)
=-1648400+1739840
=91440 k
= 91.44 kj
Teq= Delta Hrxn /Delta Srxn
= -1648400/-543.7
Teq = 3031.8 K