We were driving in our 1994 Ford Taurus when we smelled burning rubber. We pulled over and saw white smoke coming from under the hood. When we looked under the hood, we could see that a belt was broken. When standing in front of the car, the belt is located on the left side of the engine. Any idea what that belt is to?

6 cyl or V8
burning smell oil leak at rocker cover or other places hitting the zorst
exhaust joint leak

white smoke steam
welsh plug ,inlet manifold gasket , hose

The rubber smell leads me to believe a coolant hose is leaking and getting ready to burst. Better get it fixed immediately!

heater core or one of the hose did you check antifreeze level there could be a leak

Check to ensure you do not have oil dripping on the exhaust pipe. You will see discoloration from oil burning off. How can you tell it is white smoke by the smell? White vapor is usually water perhaps you have an antifreeze leak. Check your brakes, they can heat up and smell funny. I am sure you have checked the belts by now.

could be valve cover gasket.this V6 will be two.

You need to have your A/C checked as that chemical smell was the freon which is a deadly gas if inhaled.

Is there a squealing noise like the pulley may have locked up? Make sure you don't have wiring getting hot.Check all areas near the exhaust and at the firewall area where the EGR piping comes off the exhaust.
Make sure nothing is laying against the exhaust or catalytic converter. don-ohio

Bradley,
You have stated two problems. Coming to second first. Smell of burning rubber. in the car rubber is only at two places where it can burn, The tyres, unlikely as you have not commented upon your driving habits. Some people like to rev the engine so much before take off that the tyres go burning for the first few hundred meters. And then there is rubber on the wires and cables. You have to check the wires for any heat while the engine is running.
Coming to the first now. White smoke is generally of unburnt fiel and not oil. Oil alwayd give black smoke and that is the indication you get when the exhaust is giving black smoke. That means that the engine is consuming oil. if it is white then that indicates that the engine is cold and burning more gas/diesel. Is your a diesel vehicle?? But as you say it from under the hood. And that too behind the engine block. May be that the gasket is leaking from somewhere. If you could check the engine oil level for a few days early in the morning before starting the engine. If the level drops and the exhaust tail pipe does not blacken your finger when you rub it in it would mean that the oil is being burnt. Now what I suggest is that with the engine running and hand brakes on, go under the car with hood open and try to locate the source of the smoke. I am sure you would be able to locate it.
Then we talk again.

U HAVE A HEATER CORE LEAK, DOES THE SMOKE SMELL SICKY SWEET? AS FAR AS THE CEL GOES HAVE THE SYSTEM TESTED FOR FREE BY ANY KRAGEN AUTO OR AUTOZONE, JUST ASK FOR A OBD 2 TROUBLE CODE TEST, THEN POST THE CODE BACK HERE FOR US TO LOOK AT AND TRY AND DEVELOPE A FIX STRATEGY.