Crystallizing Borax - Student Activity

 

Materials

 

Procedure:

 

Part I - Making a pipe cleaner ornament

  1. Shape pipe cleaners into a design
  2. Attach pipe cleaner to a string
  3. Hang string from a pencil

Part II

  1. Use a graduated cylinder to add 700 ml of tap water to a 900 ml beaker
  2. Place 250 ml beaker (or plastic cup) on a balance and record its mass
  3. Add 250 grams of borax to the beaker and record the mass of the beaker and the borax to the nearest tenth of a gram
  4. Slowly add one teaspoon of borax to the water. Stir until all the borax has dissolved before adding any more borax.
  5. Continue to gradually add borax to the water until no more will dissolve after you have stirred the solution for two minutes. The solution is now saturated.
  6. Use a thermometer to record the final temperature of the saturated solution and record in the data table.
  7. Mass the beaker or plastic cup and the remaining borax and record.

Part III

  1. Heat the borax solution made in part I to 40oC using a hot plate
  2. Once the solution has reached 40oC, remove the beaker from the hot plate.
  3. Continue adding borax from the remaining cupful in part II. Stir in each teaspoon of borax until it has dissolved.
  4. Continue to gradually add borax to the water until no more will dissolve after you have stirred the solution for two minutes. The solution is now saturated.
  5. Mass the plastic cup and the remaining borax and record.

Part IV

  1. Place the beaker on the hot plate and heat the borax solution made in part II. Once the solution has reached 60oC, remove the beaker from the hot plate using a hot pad.
  2. Continue adding borax from the remaining cupful in part III. Stir in each teaspoon full of borax until it has dissolved.
  3. Continue to gradually add borax to the water until no more will dissolve after you have stirred the solution for two minutes. The solution is now saturated.
  4. Mass the plastic cup and the remaining borax and record.
  5. Place the beaker on the hot plate and heat until the solution changes from cloudy to clear. Then remove from the hot plate using a hot pad.

Part V

  1. Gently lower the pipe cleaner ornament into the borax solution.
  2. Rest the pencil across the top of the beaker so that the ornament is suspended in the solution without touching the bottom or sides of the beaker. (three ornaments should fit in one beaker)
  3. Set aside for 24 hours
  4. After several hours you should see crystals begin to appear. Remove the crystal ornament from the solution and allow to air dry.