(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The change in internal energy for the combustion of 1.0 mol of octane at a pressure of 1.0 atm is 5084.5 Kj. If the change in enthalpy is 5074.2 Kj, how much work is done during the combustion? Find work in Kj.

2. Relevant equations

[tex]\Delta[/tex]E=[tex]\Delta[/tex]H + (-P[tex]\Delta[/tex]V)

w=-P[tex]\Delta[/tex]V

3. The attempt at a solution

[tex]\Delta[/tex]E=5084.5Kj

[tex]\Delta[/tex]H=5074.2Kj

5084.5-5074.2=-1atm([tex]\Delta[/tex]V)

-10.3=[tex]\Delta[/tex]V

w=-(1)(-10.3)=10.3

10.3L*atm x 101.3J=1043.39J

[tex]\frac{1043.39}{1000}[/tex]= 1.04339 Kj

This is an online homework set, so when I input the answer it usually will give me a hint if I am close, but I am not getting anything. Can anyone spot my error? Thanks in advance.

Joe

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# Homework Help: Enthalpy and stoichiometry

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