Thursday, July 31, 2008

Grade School Science Fun with a Nine Volt Battery

I have a bit of fun with a nine volt battery and a container of electrolyte.

What did I learn?

1. Hydrogen makes really fine bubbles.

2. Oxygen makes relatively large bubbles

3. Hydrogen is attracted to the negative terminal

4. Oxygen is attracted to the positive terminal

5. The relative bubble sizes can be explained by the atomic weight of the two molecules. Since hydrogen is so light, it stands to reason that it would tend to breakaway from the electrode sooner than the oxygen would.

6. One proof is in the oxidation that occurs on the positive electrode of the battery.


Anonymous said...

Egg on my face-in when of my previous post I asked that question in around about way-you have just partially answered it. How would the neutral plate affect this production besides increasing the resistance as well as lowing the heat?

Charlie Ehler said...

I doubt the egg part. It's impossible to know everything.

I think the short answer is the increased distance between the positive and negative electrode is what is reducing the heat. The neutral plate is providing bonus surface area for electrolysis to occur on due to the magnetic effect of the electrode.

The reason I think electrolysis occurs is the water molecules in proximity to the plates are affected by the charge of the plate. Namely, the positively charged hydrogen is attracted to the negative plate and the negatively charged oxygen is repelled. The closer you get to the plate the greater the disassociation effect until the electrochecmical bond is broken by the charge of the plate and the injection of a free electron passing by in the electrical current. The opposite occurs on the positive plate for the opposite reason.

So it stands to reason that once the polarity and current is established the limit of gas production is quickly achieved. More current just produces heat as the water molecules that are farther away from the electrode are unaffected by the polarity of the electrode but still must pass electrons.

I think increasing voltage and reducing current may achieve more in terms of forcing the water molecules apart by increasing the magnetic effect at the electrode than increasing the current will.

Only a test will tell.

An interesting test would be to add a magnet to the back side of an electrode to see what happens.