Perform a safe, microscale simulation of acid rain formation in a plastic bag.  

     Chemicals react to form a visible brown cloud of nitrogen dioxide which, in turn, acidifies water present in the system.  An acid-base indicator shows the speed and degree to which the pH is altered.  The results are direct and unmistakable - and it all takes place within a bag on an overhead projector!  The procedure is also easily adaptable as a classroom activity. 

Concepts:  Environmental chemistry, acid-base indicators indicators

Time Required:  15 minutes

Chemicals Needed:  Zipper-lock bag, 12-well reaction plate,   

                                     copper wire, nitric acid solution, and universal 

                                     indicator solution.