Monday, September 20, 2010

The Chemical Composition of Water

Separating water into Hydrogen and Oxygen gas
Exploring Creation with Physical Science
Experiment 4.1    Apologia

Our experiment today used a 9-volt battery, salt water made with Epson salt, a glass, 2 test tubes, and safety glasses.  By using the battery, we were breaking the water molecule down to hydrogen gas and oxygen gas.

First, we made the salt water and submerged the battery for ten minutes, terminals up, to remove the trapped air from the battery.

Next, we used a large mixing bowl to make more of the salt solution.  We then filled the test tubes completely with the solution.  After carefully moving the filled test tubes to the glass with the battery, we simultaneously placed them upside down over the battery's terminals.  We made sure we had no air in the tubes by keeping the tips immersed in the salt water.

Once the test tubes were collecting the Oxygen and Hydrogen, we monitored the experiment to see how much of each gas was produced.

We learned that the negative terminal battery produced hydrogen gas while the positive terminal collected Oxygen. (Hydrogen is on the left!)  There was twice as much Hydrogen as Oxygen. With our simple experiment, we were able to "see" the chemical formula for water - H(2)O.

Each experiment requires a written laboratory report.  Michael is working on his for this lab!

I Love Science!

Add a link to your blog highlighting your science adventures.  A link back here is nice but not required.  If you don't have a blog, leave a comment.  I am looking forward to hearing about your experiments -- the ones that worked and the ones that.. oh, didn't!


  1. Oh, I just found your science linky! We're supposed to so our science experiments on Thurs, I'm hoping to catch some pictures. Maybe I can write a post and link then?

    What a cool experiment! We're using Apologia's Exploring Creation Through Astronomy and we're loving it so far. =)

  2. What a fun experiment!! What a great way to dive in & learn Science! :)
    Stopping by from Hip Homeschool Hop!

  3. Wow, my kiddos are little but I know one little boy who would love doing this experiment!

    Stopping in from the hip homeschool hop.

  4. How cool!

  5. That is fabulous! I love Apologia.

  6. We use Apologia science for both my, using General Science the other Flying Creatures...I love using materials for the Apologia Science series. Thank you for sharing the cool experiment! Science is awesome! ;0)

  7. This is a very cool experiment! We are using Apologia (Exploring Creation with Astronomy) for the first time this year and are loving it!

  8. I have two elementary-aged children, and I'm thinking of using Apologia science next year. I know it would be a while before we would get to this point, but this makes me excited to make the switch! What a fabulous experiment! I'm wowed!


  9. When we did this experiment in class, we continually found that there were 3 hydrogen for every 1 oxygen. What could be some factors that contributed to the uncertainty of our experiment?


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