Anonymous
Anonymous asked in Science & MathematicsChemistry · 9 years ago

# Hess's Law - Enthalpy?

Hess's Law Practice Problem: Calculate the heat of reaction of the following reaction using the thermochemical data in the table below.

FeO(s) +CO(g) Fe(s) + CO2(g)

Thermochemical Data:

Reaction Heat of Reaction (deltaH)

(kJ/mol)

Fe2O3(s) + 3 CO(g) 2 Fe(s) + 3 CO2(g) -28

3 Fe2O3(s) + CO(g) 2 Fe3O4(s) + CO2(g) -59

Fe3O4(s) + CO(g) 3 FeO(s) + CO2(g) 38

Relevance
• 9 years ago

Fe2O3(s) + 3 CO(g) ---> 2 Fe(s) + 3 CO2(g) -28

3 Fe2O3(s) + CO(g) ---> 2 Fe3O4(s) + CO2(g) -59

Fe3O4(s) + CO(g) ---> 3 FeO(s) + CO2(g) 38

flip second

flip third

Fe2O3(s) + 3 CO(g) ---> 2 Fe(s) + 3 CO2(g) -28

2 Fe3O4(s) + CO2(g) ---> 3 Fe2O3(s) + CO(g) +59

3 FeO(s) + CO2(g) ---> Fe3O4(s) + CO(g) -38

times first by 3

times third by 2

3Fe2O3(s) + 9 CO(g) ---> 6 Fe(s) + 9 CO2(g) -84

2 Fe3O4(s) + CO2(g) ---> 3 Fe2O3(s) + CO(g) +59

6 FeO(s) + 2CO2(g) ---> 2Fe3O4(s) + 2CO(g) -76

Add. What you wind up with is this:

6FeO(s) +6CO(g) ---> 6Fe(s) + 6CO2(g)