## 8.31

Sabah Islam 1G
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am

### 8.31

How do you find the molar heat capacity of Kr at constant pressure and constant volume? I understand that the molar heat capacity at constant pressure is 5/2R and at constant volume is 3/2R, but how do you use those values in the calculations?

Lisa Tang 1C
Posts: 62
Joined: Fri Sep 29, 2017 7:05 am
Been upvoted: 2 times

### Re: 8.31

You would use the equation for heat: q = C x delta T. Plug in the value of (5/2)R for C for part a and (3/2)R for part b. Because these are the molar heat capacities, you also have to convert the grams into moles. Hope this helps.

Ya Gao
Posts: 52
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 1 time

### Re: 8.31

Hey, how do you know the molar heat capacity is 5/2R and 3/2R ? Can you explain a little bit?

Sabah Islam 1G
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am

### Re: 8.31

Both molar heat capacities (Cp= 5/2R and Cv=3/2R) are given constants that can be found on the Constants and Equations sheet that is found on Dr. Lavelle's website and given to us during tests. Also, the R in both constants is the gas constant 8.314 JK^-1mol^-1. Hope this helps :)