How to Find Final Temperature with Constant Pressure and Changing Volume

[cdotter]

Homework Statement

645 J of heat is transferred to 0.185 mol of air inside a cylinder with volume 0.40 L. The air is at initial pressure is 3.00E6 Pa and temperature 780K.

Find the final temperature if the cylinder volume is allowed to increase while pressure remains constant.

Homework Equations

W=p(V2-V1)

The Attempt at a Solution

I have literally no idea how to do this problem. The examples in the book are (once again) unlike this problem. The question doesn't even make sense. It doesn't say what the final volume is.

 

[ideasrule]

If the pressure remains constant, you know whatever work the cylinder does is given by W=p(V2-V1). Can you use dE=Q-W to solve for V2?