Ask an Expert: Growing Borax Crystals - problem

We are trying to grow borax crystals in 3 different temperatures. Room temp, refrigerator and ice bath. We saturated the hot water with Borax (about 4 tablespoon per cup of water). We have three glasses each with a string submerged in the solution. We started over five hours ago and so far there are no crystals on any string, that I can see. Although all three glasses are coated with crystals. What could be wrong? Does it matter what kind of string we are using? Ours is a bit smooth and silky.

Hi,

Welcome to science buddies!

Are your doing this excellent project?

http://www.sciencebuddies.org/science-f ... p082.shtml

Your project has been successful; the crystals have just grown in the wrong place. They will continue to form on the sides of the glass as the water evaporates as crystals tend to form on any solid surface available. Can you take photographs and make conclusions with the results that you have?

It's possible that your string was too smooth and did not provide a suitable surface for crystals to form. Or, it's possible that there were particles of dust on the sides of the containers that were available for crystal formation. Was your saturated solutions perfectly clear, or were there any small undissolved particles that could have allowed crystals to start forming?

If you have time to repeat the experiment, do make sure that the containers are perfectly clean with no fingerprints or other particles; make sure the saturated solution is completely dissolved and clear, and definitely try using a string with a rougher surface. This should solve the problem. However, if you don't have time to repeat the experiment, you do have results that you can write up. Your explanation of why the crystals formed on the sides of the containers will make a good discussion section.


I hope this helps. Please let us know if you have more questions.

Donna