# fnt14 - FNTs from DL 14 4.1-8 What is the physical basis...

This preview shows pages 1–2. Sign up to view the full content.

FNTs from DL 14 4.1-8) What is the physical basis for the difference in measured values of C p and C v for a gas? The physical reason why C p and C v have different values is that C v is measured when our volume is constant and unchanging, so no work is done on or by the system. Heat capacity is equal to the heat gained or lost by the system, divided by the change in temperature [ C = Q/(change in T) ]. When no work is done, our change in internal energy (delta U) is equal to the heat. When we calculate C p , our system remains at constant pressure but our volume can change. So whenever we add Q (and increase T), our volume changes (PV = nRT), which means work is done ( W = -P *(change in Volume)). In this case, our heat is equal to our change in internal energy minus whatever energy changes are due to work. Using PV = nRT and W = - P*(delta V) and p(delta V) = nR (delta T) , we can find the relationship between C p and C v to be: C p = C v + nR so C p > C v always 4.2-2) a)W = Area under the curve = -1150J, we know its negative because the change in

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 2

fnt14 - FNTs from DL 14 4.1-8 What is the physical basis...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online