Enoch
Dec12-04, 04:33 PM
Sorry for the second question in just a day, but my proffessor really didn't cover this material very well. Thanks for any help given :).
A cylinder contains 4.22 mol of helium gas at a temperature of 314 K. The molar specific heat of helium at constant volume is 12.5 J/K mol. How much heat must be transferred to the gas to increase its temperature to 531 K if it is heated at a constant volume? Answer in units of J.
Well, after reading the problem, I knew that it was an Isochoric Thermal process due to the comment "heated at a constant volume". Therefore this equation applies:
Change in Internal Energy = Q - W
- The work is going to be 0 joules
- Amended equation: Change in internal Energy = Q
Q = Cn(Tf - Ti)
- Solving for that: Q = (12.5)(531 - 314) = 2712.5
I plugged that in as my answer, and it was wrong. Where did I go wrong? Is the problem even setup right from my perspective?
A cylinder contains 4.22 mol of helium gas at a temperature of 314 K. The molar specific heat of helium at constant volume is 12.5 J/K mol. How much heat must be transferred to the gas to increase its temperature to 531 K if it is heated at a constant volume? Answer in units of J.
Well, after reading the problem, I knew that it was an Isochoric Thermal process due to the comment "heated at a constant volume". Therefore this equation applies:
Change in Internal Energy = Q - W
- The work is going to be 0 joules
- Amended equation: Change in internal Energy = Q
Q = Cn(Tf - Ti)
- Solving for that: Q = (12.5)(531 - 314) = 2712.5
I plugged that in as my answer, and it was wrong. Where did I go wrong? Is the problem even setup right from my perspective?