## HW 4.19

$\Delta U=q+w$

Hannah Lee 2F
Posts: 117
Joined: Thu Jul 11, 2019 12:15 am

### HW 4.19

Calculate the molar kinetic energy (in joules per mole) of Kr(g) at (a) 55.85 8C and (b) 54.85 8C. (c) The difference between the answers to parts (a) and (b) is the energy per mole that it takes to raise the temperature of Kr(g) by 1.00 8C. What is the value of the molar heat capacity of Kr(g)?

I used the equation Um = 3/2nRT for both (a) and (b), with R = 8.314 J/mol x K and T converted to K. For 4.19, I got (a) 4101.3 J/mol, (b) 4113.8 J/mol, but it doesn't seem to match up with the solutions manual. Can someone point out where I went wrong?

705302428
Posts: 50
Joined: Sat Aug 24, 2019 12:16 am

### Re: HW 4.19

Section 4.C.3 from the textbook might be helpful to look at.