ChemLab #1 - Shape of NaCl Crystals
Date of Lab:   Score:
Lab Group Members:   This is an individual lab to be done AT HOME.
Problem Statement: What is the shape of NaCl (salt) crystals?
Hypothesis:
 
Research References:   Lab Key
Experimental Design Daily Observations
Equipment List:
  • non-iodized table salt   (iodized salt will work - just not as well)
  • water
  • small saucepan
  • glass container
  • paperclip
  • cotton string
Procedure:
  1. Pour one cup of water into a small saucepan.
     
  2. Place the saucepan on the stove with medium heat.
     
  3. Slowly add 11/4 cups of non-iodized table salt while stirring.
     
  4. Temporarily remove the saucepan from the heat if the liquid begins to boil.
    (You need hot water, but not boiling)
     
  5. Continue to stir until all the salt is dissolved.
    (You can add more water - but not too much! The solution must be supersaturated!)
     
  6. Remove saucepan from heat and allow the solution to cool for five minutes.
     
  7. Pour the cooled solution into a clean glass container.
    (NO undissolved salt can go into this container!)
     
  8. Tie a paper clip to the end of a cotton string.
     
  9. Tie the other end of the string to a pencil and complete the set up shown in the diagram.
     
  10. Place the container where it will remain undisturbed for 2 weeks.
     
  11. Record observations of the contents of the jar daily.
     
  12. At the end of two weeks (or when all the liquid has evaporated), remove the string and crystals. Let the crystals air dry. DO NOT remove the crystals from the string.
     
  13. Bring ONLY the crystals and your observations to class.