The discussion revolves around calculating the heat transferred into a closed system using the ideal gas law, specifically in the context of a cylinder piston system being heated. Participants explore the application of the first law of thermodynamics and the appropriate equations to use for this scenario.
Participants express differing views on whether to use Cv or Cp for the calculations, indicating a lack of consensus on the appropriate approach to take in this context.
There are unresolved questions regarding the calculation of ΔU and the definitions of work done in the context of constant pressure versus variable volume.
Using the first law of thermodynamics, how would you answer this question?Axe199 said:So i am making a simple demonstration of ideal gas law using a cylinder piston system, heating the system so the piston is pushed up, i wanted to calculate the heat transferred into the system, will it be Cp(Tf-Ti) or Cp(Tf-Ti)+ work done by the system ?
well using the first law Q-W=ΔU, Q will equal to to ΔU+ W but i don't know how to calculate ΔUChestermiller said:Using the first law of thermodynamics, how would you answer this question?
For one mole of an ideal gas, ##\Delta U =C_v(T_f-T_i)##. Now what?abdo799 said:well using the first law Q-W=ΔU, Q will equal to to ΔU+ W but i don't know how to calculate ΔU
why use Cv not Cp the system has constant pressure and variable volumeChestermiller said:For one mole of an ideal gas, ##\Delta U =C_v(T_f-T_i)##. Now what?
The internal energy of an ideal gas is (a) a function of temperature only or (b) a function of temperature and volume (per unit mass)?abdo799 said:why use Cv not Cp the system has constant pressure and variable volume