`Rate of SolubilitySharon Barfield                Perkins Bass                               1140 W. 66th St.                               Chicago IL 60621                               (312)535-3275Objective:          This can be adapted for any grade.  Discover factors affecting the rate of solution.  Materials Needed:          The materials are for each group of four.1.  Test tube with cork                         9.  Sugar cubes2.  Two clear plastic cups                     10.  Aspirin3.  Pestle                                     11.  Salt tablets4.  Mortar                                     12.  Mint candy5.  Clock with second hand or stopwatches      13.  Water6.  Alcohol burner                             14.  Alka Seltzer7.  Goggles                                    15.  Junior Mints 8.  Mints                                      16.  Tongs    Strategy:   1.  Introduce and discuss solvent, soluble, solute, insoluble, and rate. 2.  Demonstrate what the students will be expected to do using the vocabulary      introduced. 3.  Discuss safety and have groups get materials, including instruction sheet. 4.  Fill containers with water as marked.  Test tubes-room temperature;     Cups-one room temperature, one cold. 5.  One solute will be dropped into each solvent.  Make a hypothesis about      what will happen before adding the solutes.   6.  Place one test tube over the flame, holding it with the tongs.  Place the      cork in the second tube and shake.  7.  Use the mortar to crush the solute and put it in the cup containing room      temperature water.  Drop a solute into the cold solvent and let it sit.  8.  Record the length of time needed to dissolve the solvents.  If a solvent      hasn't completely dissolved in 5 minutes write 5+ on your chart and discard      all solvents. 9.  Repeat steps 4 through 7 for the remaining solutes, except for the Junior     Mints.10.  Pass out a new set of instructions and the Junior Mints.11.  Each student will place one Junior Mint in his/her mouth.12.  Do not move it around.  Time how long it takes for it to dissolve.  Write     down every member's time.  13.  Now put one in your mouth and move it around.  How long did it take to      dissolve?  Write down the fastest time for the group.14.  The group members with the fastest time will compete against each other.15.  Put a Junior Mint in the mouth and move it around.  The one who dissolves     the mint first is the winner.16.  Discuss what took place.  Discuss whether their hypotheses were correct.17.  Review vocabulary and factors that affect the rate of solubility.     18.  Have the students act out what the molecules of the solute are doing when      a solvent is being heated, when it is cold, when it is being shaken, and      when it is just sitting at room temperature.  Performance Assessment:Given an unknown solute, determine which method used in the experiments willbe fastest in dissolving the solute.  The group dissolving it first will receive extra credit points.                                      Conclusion: The students will discover which method works the fastest to dissolve a solute and be able to apply the information gathered to real life situations.          `