[taniasalgueiro]

Hi there again!

I'm in trouble. I had a MDSC, like I said in others posts, and now I have a cp curve and a flux heat curve.

First, I wanna know if latent heat, and fusion enthalpy are the same.

I'm working in TA Universal Analysis and I made the area in the two curves and the results were different. Which one, you think I should use?

I attached an image with the two curves to better explain.

Thanks in advance.

[mjc123]

Yes, enthalpy of fusion and latent heat of fusion are the same.

You have drawn your baselines badly. Especially on the blue curve, you are not integrating anything like the whole peak. Choose integration limits where the signal has returned to baseline, as far as you can judge. See if you get the same for both curves. (Was there anything in the nonreversing heat flow curve?)

[taniasalgueiro]

Thank you for your answer, really!

I have a explanation to have do the baselines with this limits. I will try to explain. Well, we tried to know the phase change, and the limits I did the baseline are the limits that we think where it is the phase change. So, for your answer i guess it's really wrong. So, to have my latent heat, I have always to choose integration limits where the signal has returned to baseline?

Well, I did new limits, but the results are different again.

I'm sorry, I did not understand your question for nonreversing heat flow curve. I have one, but I don't understand what it's for.

And one thing, in one curve or another, is supposed to give the same or approximate. Is it?
Thank you.

[mjc123]

The points where the signal leaves and returns to the baseline tell you the range over which the phase change occurs (assuming there are no other processes overlapping).
The nonreversing heat flow records any irreversible thermal processes occurring. If there are no features in this curve in the region of interest, then the enthalpy of fusion calculated from the heat flow curve and from the rev Cp curve should be the same.
"One thing" is supposed to give "the same" as what? I don't understand your question.