Heating Capacity


Moderators: Chem_Mod, Chem_Admin

Tiffany Cao 1D
Posts: 94
Joined: Fri Sep 29, 2017 7:03 am
Been upvoted: 1 time

Heating Capacity

Postby Tiffany Cao 1D » Sun Feb 04, 2018 2:26 pm

In which cases would we use 3/2*R=Cv and 5/2*R=Cp? I noticed in 9.43, the solution used the actual heating capacity of water(75.29J/Kmol), but when would we ever use the other heating capacity rules?

Curtis Wong 2D
Posts: 62
Joined: Sat Jul 22, 2017 3:00 am

Re: Heating Capacity

Postby Curtis Wong 2D » Sun Feb 04, 2018 2:31 pm

In Problem 9.43, we use the molar heat capacity of water in a liquid form because we have that information to do so. We know the heating capacity of water, and we needed to find the temperature in K (which is why we used Molar heat capacity).

In regards to your other questions, the R is the ideal gas constant, so we would only use the Heat Capacity of an Ideal Gas at Constant Value (Cv) or the Heat Capacity of an Ideal Gas at a Constant Pressure (Cp) when we are working with ideal gases (also depends on whether or not they're diatomic as well).

Ivy Lu 1C
Posts: 54
Joined: Thu Jul 27, 2017 3:00 am

Re: Heating Capacity

Postby Ivy Lu 1C » Sun Feb 04, 2018 3:12 pm

The heat capacities, 3/2*R=Cv and 5/2*R=Cp, relate to when there is an ideal gas at constant volume/pressure. For this problem, the water is in its liquid state, so the heat capacity of an ideal gas would not apply.

veneziaramirez 3I
Posts: 57
Joined: Fri Sep 29, 2017 7:07 am

Re: Heating Capacity

Postby veneziaramirez 3I » Sun Feb 04, 2018 11:11 pm

Does it matter which equation we use to find heat capacity? Will the formula for specific heat capacity and molar heat capacity give the same thing?

Return to “Entropy Changes Due to Changes in Volume and Temperature”

Who is online

Users browsing this forum: No registered users and 2 guests