When 1 mol of a fuel burns at constant pressure, it produces
3452...

Question

When 1 mol of a fuel burns at constant pressure, it produces
3452 kJ of heat and does 11 kJ of work. What are ΔE and ΔH for
the combustion of the fuel?

Accepted Answer

hey everyone in this example we need to calculate our change in energy and our change in entropy for a system at constant pressure When it absorbs 211 kg of heat and does 32 kg joules of work. So we should recall our first formula for change in energy, which is going to equal our value for heat plus our value for work. So next we also want to recall that our value for change in entropy is going to equal our value for heat at constant pressure, which is exactly what they say we have in this example. So we can already say that our value for our change in entropy is going to equal positive 211 kg jewels. And that is due to the fact that our value for Q is equal to 211 kg jewels at constant pressure. So we already have one answer that's already known. And so the next step is to go ahead and find our value for delta E. So we would say that our delta E. Is equal to r value for heat which is given again as positive to 11 kg joules added to our value for work. And our work value is given to us as 32 kg jewels. But because our system is doing the work, we would go ahead and make that value for w negative. So we would add negative 32 kg jewels. So system does work corresponds to a negative value for W. So what we would get for our change in our energy is going to equal a value of 179 kg jewels. And so this would complete this example as our full two final answers, our value for the change in energy and our value for the change in entropy. So I hope that everything I went through is clear, but if you have any questions, please leave them down below, and I will see everyone in the next practice video.

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