Calculate Enthalpy Change: C6H5OH, CO2, H2O

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SUMMARY

The discussion focuses on calculating the change in enthalpy for the combustion reaction of phenol (C6H5OH) producing carbon dioxide (CO2) and water (H2O). The enthalpies of formation provided are C6H5OH at -165 kJ/mol, CO2 at -393.15 kJ/mol, and H2O at -285.83 kJ/mol. To determine the enthalpy change, participants emphasize the necessity of a balanced chemical equation and identifying the missing reactant, which is oxygen (O2). The formula for calculating the change in enthalpy is given as ΔH = ΣνiΔH°products - ΣνjΔH°reactants.

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Homework Statement


determine the change in enthalpy for the following reaction from the enthalpies of formation for the reactants and products. (C6H5OH -165 kJ/mol, CO2 -393.15 kJ/mol, H2O -285.83 kJ/mol)


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The Attempt at a Solution


No idea, been a while since I did this...if ever

Any direction is appreciated.
 
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A change in enthalpy would indicate that there were parameters in the question that were changing. Do you have initial or final temperatures or any other data?

-Mark
 
Start with the balanced reaction equation.
 
##\Delta H= \sum_i \nu_i \Delta H^0_{products}- \sum_j \nu_j\Delta H^0_{reactants}##

As Borek says, you should start by having the balanced chemical equation.
 
Last edited:
As Borek said, you have to start out with a balanced reaction equation. But you do realize that there is a reactant missing from the problem statement? Ask yourself, what is it the C6H5OH has to be reacting with to produce CO2 and H2O? (hint: it's a combustion reaction). So, what is the missing reactant. The next thing you have to recall is that, if this reactant is an elementary substance, what is its heat of formation? How is the heat of reaction related to the heats of formation of the products and the reactants?
 

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