Science Buddies: "Ask an Expert"

I am trying to heat water to certain temperatures (70, 80, 90 degrees celsius) for an experiment. I am heating water (3ml)inside a small test tube over a bunsen burner and have found myself quite incapable of maintaining the water's temperature long enough to dissolve an amount of sodium thiosulfate within the water for a crystallization experiment as when I remove it from the flame it cools, and if i leave it over the flame it gets too hot. How would i be able to maintain the waters temperature at a set value for an extended amount of time?

Hello,

Do you have access to a heating block or a heating water bath? If so, you could set the heat block or the water bath to the appropriate temperature and then incubate your tube for extended periods of time.

Hope this helps,

Mary

Hi!

I found this how-to article online when I googled adjusting the heat on a bunsen burner.
Instead of completly taking the tube off the flame you could find a cooler part of the flame

http://www.nclark.net/Bunsen_Burner_Lab.doc

Hope this helps!

Heat a large pot of water on the kitchen stove...it is much easier to maintain a given temperature in the large pot, especially if it is a gas stove. Then you can simply place the test tube in the large pot.