2004 Dodge 2.0sx. On the passenger side near the front right side of the engine is a wheel that should have a belt on it. Its totally exposed and is somewhat located over the passenger tire. What does this belt do? and what size/kind is required to fix it?

 

Sounds like it is the Power Steering belt, which in reference to your other thread, is probably why you no longer have it. Part number is in the maintenance thread.