# Physical Chemistry 1st Law of Thermo

## 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

$$\Delta$$U=q+w

Cv 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 $$\Delta$$U=q and then set nCv$$\Delta$$T=q=1,000?

## Answers and Replies

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 $$\Delta$$U 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!