Sewer Lice

Jones, Mamie                   Rosa Parks Middle School
                               371-9575
                          

Objectives:

1. Demonstrate forces of adhesion and cohesion and equilibrium density.
2. Explain that if the pressure on a gas decreases, the gas will
   expand.
3. Measure the volume of CO2 in a bottle of soda pop.
4. Explain the effects of various temperatures on the solubility
   of carbon dioxide.

Apparatus Needed:

   4 bottles of Seltzer water or other carbonated beverage, 
   beakers, 2 L plastic pop bottles, raisins, pop corn, spaghetti 
   pieces (soaked for 2 hours), ring stand, ring stand clamp, large 
   pan of water, rubber tubing, one hole rubber stopper, glass bend, 
   tape, ice cold and hot (not boiling) water.  
  
Recommended Strategy:

  Place raisins in beaker, pour colored seltzer water into the beaker. 
  Into a second beaker containing seltzer water, place pieces of 
  broken spaghetti. Into a third beaker of seltzer water, place 8 
  kernels of popcorn. Observe.
                                                                              
  Remove the cap from a bottle of cold carbonated beverage. Quickly
  place a balloon over the mouth of the bottle and seal tightly with
  tape. Shake the bottle briefly. When the balloon is about the size 
  of an apple, squeeze it firmly with both hands. Alternately squeeze
  and release the balloon.
  
  Calibrate a 2 liter pop bottle. Fill the bottle with water. Invert 
  the full bottle into a large plastic tub or pan of water. Clamp the 
  bottle to a ring stand. Remove the cap from an ice-cold bottle of
  seltzer water. Immediately insert a stopper  (assembled for  
  collecting gas) into the bottle of seltzer and place the other end 
  of the rubber tubing beneath and inside of the open end of the 
  inverted bottle. The tubing should reach all the way into the bottle. 

  Place the bottle of seltzer water inside a large beaker of hot
  (but not boiling) water. Shake the seltzer water occasionally to
  dislodge bubbles and to speed up the process. When the production  
  of gas has stopped, mark the level of water in the inverted bottle 
  with a wax pencil or tape.
  
Evaluation:

  1. Explain why the raisins, spaghetti, and popcorn moved up and down 
  through the seltzer water. 
    
  2. What happens to CO2 when the balloon was squeezed? released? 

  3. How much gas did you collect from the bottle of seltzer water?

  4. What can you say about the solubility of a gas as temperature 
  changes?