Ok, I still don't understand question 27 from chapter 9 and I have looked thououghly through what has been posted thus far. How are we supposed to calculate dH and dE? I tried calculating them the exact waythat was posted (dH = (5/2)*d(PV) and the answer is not correct. The same is true for dE. And I don't really understand why we should calculate dT if we never use it. Thanks and I'm sorry if I just don't see the answer and it is really there.

-- Anonymous, February 07, 2000

Answers

Remember that d(PV)=((P2*V2)-(P1*V1))

((6atm*20L)-(3atm*55L))=-45 L*atm

dH = (5/2)(-45Latm)=-113 L*atm

dH = (-113Latm)*(101.3J/Latm)= 11396J = 11kJ

Go back and reread the rest of the posted answer to see if you can figure out dE.

-- Anonymous, February 07, 2000