You are making a supersaturated solution. That is a solution with more dissolved solid than it can hold at a certain temperature.

HOT water can hold more dissolved salt than cool water. As the solution cools, NaCl crystals will form on the string until the extra salt has been removed. At this point, the solution is "saturated", containing all the salt it can hold.

As the water evaporates, more and more salt comes out of the solution and the crystals on the string will grow.

By the end of the experiment, the crystals should be large enough for their shape to be easily seen.

To make an "A" on this lab, bring the following to class:

• The crystals (still on the string).
• The paper with your daily observations.

 

NOTE: you will not be given a printed lab report for this lab.

• If you have an Internet connection at home, access the page in that way.
   
• If you do not have an Internet connection at home do the following:
   
  • With the ChemLab #1 page open on your computer, click on "file" on the top Safari toolbar.
     
  • From the drop-down menu, click on "print".
     
  • When the print window opens, click on "PDF" in the lower left-hand corner.
     
  • From the drop-down menu, click on "Save as PDF".
     
  • Save the file to your desktop.
     
  • You now have the webpage saved on your computer and can access it any time you need it, without being connected to the Internet.

Capturing a webpage on your computer can be very helpful.
Especially if you do not have an Internet connection at home.