31.12.12

6.12.12

Happy Birthday Charles Martin Hall

Charles Martin Hall, born December 6, 1863, figured out how to produce aluminum metal in a cost effective way.  During a lecture at Oberlin College his professor, Jewett, said  "if anyone should invent a process by which aluminum could be made on a commercial scale, not only would he be a benefactor to the world, but would also be able to lay up for himself a great fortune."  At that point Hall decided that he would be the chemist to do so.  Read more about how he did it here

1.5.12

Test Tube Science: 1+1≠2


Materials:
   -Two test tubes
   -5 mL rubbing alcohol
   -5 mL water
   -One pipette  
Background:
Dissolving sugar in water is a common enough sight.  Dissolving two liquids in each other is less commonly noticed.

Directions:
Put 5 mL of rubbing alcohol in one test tube and put 5 mL of water in the second test tube.  Now use the pipette to transfer the rubbing alcohol to the water test tube.

Now look at the volume of the mixed test tube.  If the two liquids mixed but didn’t dissolve there would be 10 mL of liquid in the new test tube.  How many do you see?  Can you find any other liquids that will dissolve in each other?

13.4.12

Test Tube Science: Plop Plop Fizz Fizz


Materials:
   -Two test tubes
   -10 mL hot water
   -10 mL cold water
   -One tablet of AlkaSeltzer

Background:
The rate at which a reaction progresses depends on the temperature of the reaction.  This experiment lets observe this first hand.

Directions:
Fill one test tube with hottest tap water available.  Fill another with cold, cold water.  Break an Alka Seltzer tablet into small pieces.  Drop carefully into each test tube.  See which temperature water makes the most popping and fizzing.

8.4.12

Happy Birthday Melvin Calvin

Melvin Ellis Calvin, born April 8, 1911, using the 14C isotope as a tracer, Calvin and his team mapped the complete route that carbon travels through a plant during photosynthesis, starting from its absorption as atmospheric carbon dioxide to its conversion into carbohydrates and other organic compounds. In doing so, the Calvin group showed that sunlight acts on the chlorophyll in a plant to fuel the manufacturing of organic compounds, rather than on carbon dioxide, as was previously believed.

1.4.12

Remember, if you are not part of the solution, you are part of the precipitate.

31.3.12

Happy Birthday Robert Bunsen

Robert Bunsen, born March 31, 1811 was a German chemist known for perfecting the burner which bears his name.  While developing the field of emission spectroscopy, he co-discovered the elements cesium and rubidium along with Gustav Kirchhoff.

15.3.12

Test Tube Science: Test Tubesicles


Materials:
   -Five test tubes
   -Five barbecue skewers
   -50 mL of juice

Background:
These are fun to have on a warm afternoon.

Directions:
 Balance test tubes carefully in rack.  Fill carefully with juice.  Place in freezer for 20 minutes.  Using barbecue skewers or skinny popsicle sticks, place them upright in slushy mixture.  Freeze until firm.  Remove by running test tube very briefly under warm water.

13.3.12

Happy Birthday Joseph Priestley

Joseph Priestley, born March 13, 1733, was an English natural philosopher known for his discovery of oxygen.  As an avid supporter of the phlogiston theory, he called oxygen “dephlogisticated air” and fought against Lavoisier's characterization of it as an element.