C/P section bank #7

[akimhaneul]

For this question, why is the answer B? CAn't you do that with calorimeter too?

Based on the passage, an experimental feature that distinguishes the PAC from the classic calorimetry technique based on thermometer is that PAC

Can be used on samples with specific heats larger than water
enables the measurement of fast and localized heat transfer process
Is based on the second law of thermodynamics
Is useful on samples in the solid phase only.


Thanks!

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[rabbott1971]

In the passage, the third sentence of the paragraph following Figure 1 literally has Answer B in it word for word.

And no, I don't think a traditional or bomb calorimeter can utilize a fast localized heat transfer process. It is more like you measure the heat of the whole thing, subtract out the calorimeter, and calculate from there.

 

[aldol16]

A traditional bomb calorimeter is a closed system. Only old-school inorganic/physical chemistry labs use one of these anymore but generally what happens is you have some process going on inside the calorimeter such as a reaction of interest. You want to measure the heats involved in the system and the calorimeter does this. In short, you can stick your sample into the calorimeter and it'll measure the heat transfer in/out of your sample. Because of this design, it measure overall heat transfer and doesn't take into account any localized heat transfer processes. All you get is a global picture - much like an EEG as compared to fMRI. The calorimeter in this case would be the EEG whereas the PAC is the fMRI.