Physical Chemistry 1st Law of Thermo

[joseg707]

Homework Statement

Two containers each contain 0.500 moles of N2 initially at 300. K. One container has a fixed
volume, and the other container has a movable frictionless piston. If both containers are heated
by 1000. J energy, calculate the final temperature of N2 for each container.

Homework Equations

PV=nRT

\DeltaU=q+w

C_v for a diatomic molecule is 5R/2

The Attempt at a Solution

I don't really know how to approach this problem as no pressure or volume is given. For the first container, I realize that the volume is fixed, so no heat is lost to work. I don't really know where to go on from here though. Can I say \DeltaU=q and then set nC_v\DeltaT=q=1,000?

 

[joseg707]

For the second container, can I assume that pressure will be held constant as the volume of the container increases? The heat put into the system will then be converted into work as well and so \DeltaU will equal q+w. The temperature will increase, but not as dramatically as the first container. I don't know what to do from here though. I don't know which equation I should start with. If someone can point me in the right direction or correct me if I'm wrong, I'd greatly appreciate it. Thanks in advance!