Science Buddies: "Ask an Expert"

I did the folloiwng experiment:

https://www.sciencebuddies.org/science- ... p082.shtml

My conclusion was that the cold temperature grew the most crystals, but when i was checking why my conclusions were like that. I found out that other people and scientist did this project and there conclusions was that room temperature grew the most crystals. What is the accurate and correct conclusion?

In science, the "accurate and correct conclusion" is the one that is reached by independent researchers duplicating the results.

I have not run this experiment myself, but did take time to read the description of the project. And I do know the basics about crystal growth.

The first thing to do is create the supersaturated solution of borax. This is what you do in step 6 of the experimental procedure. If you did this correctly, and used the same solution in all three of your jars, then there is no problem here. You must heat the water to get the most borax dissolved. As the project description states, the borax begins to come out of the solution as the solution cools. So, it seems reasonable to me that the jar that cools the soonest should grow crystals first. That would be the ice bath jar. Then the refrigerator jar should show grow, followed last by the room temperature jar.

If this is what your experiment showed, then I believe you have a valid conclusion. You should talk more to those people who said the room temperature jar grew the fastest and see what differences there might be between the way you ran your experiment and the way they ran theirs.

I hope this helps.

Keep up the good work!

There is a difference between growing large borax crystals and cooling a super satruated borax solution so quickly that the borax preciptates out quickly and piles up on the bottom of the container as a powder or lots of very small crystals. Unless the containers are sealed, evaporation will also affect the results. Water will evaporate faster at higher temperatures and into drier air, so your results can easily be different than others performing the same experiment under different environmental conditions. Figuring out all of the uncontrolled environmental variables that can influence a result is what makes science challenging.