Calculate the free energy for the reaction: 2AL +Fe2O3-àAL2O3 + 2Fe given:: 2AL

Question

Calculate the free energy for the reaction: 2AL +Fe2O3-àAL2O3 + 2Fe given::

2AL + 3/2 O2 àAL2O3 DG °(initial)= (-1203KJ)

2Fe + 3/2àFe2O3       DG°(initial)= (-762)

2AL +3/2 O2  -->AL2O3          ; G1°(initial)= (-1203KJ) ---------------- ( 1 )

2Fe + 3/2 O2 -->Fe2O3              ; G2°(initial)= (-762)   -------------------- ( 2)

2AL + Fe2O3-->AL2O3 + 2Fe   can be obtained byEq ( 1 ) + reverse of Eq ( 2 )

So, G for the above equation isG=  G o1- Go2

                                                       = -1203 KJ - ( -762 KJ )

                                                       = -441 KJ

since thesecond equation is reveresed doesnt the sign change to + 762 so theequation is -1203 -(+762)? if not why???

do weNEVER change the signs?!

also, isit true that we never multiply g 1 and g2together???

Explanation / Answer

2Al +3/2 O2  -->Al2O3          ; G1°(initial)= (-1203KJ) ---------------- ( 1 )

2Al +Fe2O3-->Al2O3 +2Fe   can be obtained by Eq ( 1) +   Eq ( 3 )

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.