Solubility

I have been lab crazy.  I just can't think of any way to better teach concepts like density and solubility than through labs (with lots of discussion, of course).  So, after the M & M labs, we tried to see if different substances had difference rates of solubility.  Students had flour, salt, and sugar.  (I tried to find MSG, but I did not have time to make it to an Asian market and none could be found at our grocery stores.)  Students measured water for each container and used equal amounts of each substance, stirring for 20 seconds to see which dissolved first.  They continued stirring in increments of 20 seconds until all three substances dissolved.