Heat of Formation Propanol: ΔHf°

[a_ng116]

What is the equation for the heat of formation for propanol?

 

[dextercioby]

What reaction...?

Daniel.

 

[a_ng116]

Sorry. The whole question was:

If the heat of combustion of propanol is -1843.7 kJ/mol, what is the heat of formation of propanol? Write the equation for the heat of formation for propanol and include the energy as a term in the equation.

I got the heat of formation to be -304 kJ. I'm not too sure how to write the equation though.

 

[xanthym]

Sorry. The whole question was:

If the heat of combustion of propanol is -1843.7 kJ/mol, what is the heat of formation of propanol? Write the equation for the heat of formation for propanol and include the energy as a term in the equation.

I got the heat of formation to be -304 kJ. I'm not too sure how to write the equation though.

Propanol Combustion:
C3H8O(l) + (9/2)O2(g) → 3CO2(g) + 4H2O(g) ::: DH_c=(-1843.7 kJ/mol)

Propanol Formation:
We begin with the Propanol Combustion "reverse" reaction and add other formation reactions required to obtain the Propanol Formation equation (in RED below). During the "addition" process, entities on both sides of the equation will "cancel".

3CO2(g) + 4H2O(g) → C3H8O(l) + (9/2)O2(g) ::: DH_r=(+1843.7 kJ/mol)*(1)=(+1843.7 kJ)
3C(s) + 3O2(g) → 3CO2(g) ::: DH_f=(-393.9 kJ/mol)*(3)=(-1181.7 kJ)
4H2(g) + 2O2(g) → 4H2O(g) ::: DH_f=(-241.8 kJ/mol)*(4)=(-967.2 kJ)
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3C(s) + 4H2(g) + (1/2)O2(g) → C3H8O(l) ::: DH_f=(-305.2 kJ/mol)


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