See also: 4D50.42 in Heat and Fluids.

The air pollution slides found at 8B30.35 in the Astronomy section can be used to roughly measure the amount of pollution produced in the box for this demonstration.

Note that this demonstration will take about 15 minutes to clean up and then prep if you are going to do this more than once in a day.

The necessary items for this demonstration are in the enclosed box that is used for this demo. Also, the ammonium hydroxide is in one of the flammable cabinets, and the hydrochloric acid is in the acid cabinet.  These bottles are labeled with the date of purchase.  Make sure these are no more than 5 year old.  Both of these can be picked up at Biochem Stores.

THE DEMONSTRATION:  Place 40 ml of hydrochloric acid in one of the 50 ml plastic beakers and place it into the box.  Take a deep breath, and pour 40 ml of the ammonium hydroxide into the other 50 ml container and immediately place it in the box and close the lid.  The "smog" should form at once as a white cloud and in about 10 minutes will be so dense that you can no longer see through the box.  When done, flush with much water as you pour both of the remaining liquids down the drain.  Products of the reaction are NH4Cl (Ammonium Chloride = the cloud) and H2O (Water).

Fill the beaker about 1/2 full of hydrochloric acid and cover with the watch glass.  Fill the test tube 1/2 full of ammonium hydroxide and lightly stopper.  Place the two vessels into the Plexiglas box on opposite sides.  Leave the box open until ready to demonstrate.  Place the TV camera so that it is looking through the box at the black backstop.  When ready to demonstrate uncover the HCl and un-stopper the NH4OH and close the box.  Cloud formation will be observed almost immediately and cloud density will increase with time. After about 5 to 10 minutes the cloud will be dense enough to completely obscure the backstop.  Products of the reaction are NH4Cl (Ammonium Chloride) and H2O (Water) Spills and disposal of both the chemicals should be treated by flushing with water.