6.1 - The Diffusion Chamber
22. The Diffusing Checkers Model
23. Deriving the Motion of Molecules
24. Diffusion Chamber
25. Location of the Precipitation Point
15. The Diffusion Chamber Simulation
Ammonia gas is invisible as it moves through the air from Barry's opened bottle to Jennifer's nose. There is a simple demonstration that makes visible some consequences of this motion of ammonia. The demonstration uses what is called a diffusion chamber. This is a popular chemistry experiment in which two different gases, typically ammonia (NH3) and hydrogen chloride (HCl) diffuse from opposite ends of a closed glass tube (Figure ). Eventually the two gases meet and react, forming a disk of white dust made of the solid ammonium chloride (NH4Cl). We say that the ammonium chloride is precipitated out of the gas.
Later you will be able to perform this experiment using small tubes supplied in your laboratory kit.