Science+Experiment+Redox+Demo

This is supposedly the explanation for the Rusty Ball Bearing and the Aluminum covered ball. The actual name for the reaction is called....

THERMITE REACTION! Whooo! Okay...

My boy, Steve Spangler, will demonstrate what Jen did in class as well as give you a little bit more information about the amount of heat that actually occurs during the reaction and why the reaction happened. Add more to this, people! :)

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I believe that the experiment we observed today with the rusted iron balls and the aluminum is a version of the Thermite Reaction. From my understanding the rust (iron oxide) and aluminum underwent a redox reaction thus creation iron and aluminum oxide.

Fe2O3 (s) + 2 Al (s) --> Al2O3 (s) + 2 Fe (l)

There's a question in the textbook that asks for the half equation of this. It looks like this: Oxidation half-equation: Al --> Al^3+ + 3e- Reduction half-equation: Fe^3+ + 3e- --> Fe

This is what the dangerous thermite reaction looks like: media type="youtube" key="a8XSmSdvEK4?fs=1" height="385" width="480"

MUST WATCH. I don't know if this is relatable but Mythbuster took some 11 lbs of thermite and some ice and lit it up until it explodes. It's pretty cool.

media type="custom" key="6937693" Hey guys I also found this video online and its really good!!! These two guys want to see what happens when you put a pot of thermite reaction powder on a car... WATCH IT!!! media type="youtube" key="rdCsbZf1_Ng?fs=1" height="385" width="640"

**Floating Penny Demo** First off, it's important to know that pennies are usually made with a Copper outer layer and a Zinc Core. Evidently the Copper on the outer part of the penny has oxidized with Oxygen to form CuO(s).

Then Jen placed the penny in high concentration HCL (aq), which caused two reactions to happen:

1. The outer layer of the penny : CuO (s) + 2 HCl (aq) > Cu2+(aq) + 2 Cl-(aq) + H2O (l) 2. The inner core of the penny: Zn (s) + 2 HCl (aq) > Zn2+(aq) + 2 Cl- (aq) + H2 (g)

So as the zinc dissolves into the solution, it leaves the penny behind, which is now just an outer shell of copper, that is much lighter than the solution, then causing it to float to the top :)

I'll add in that the penny has to be made in the years where they put zinc in the core. Composition of Canadian penny: ([|source])

98% copper, 1.75% tin, 0.25% zinc 98.4% zinc, 1.6% copper plating 94% steel, 1.5% nickel, 4.5% copper plating or copper plated zinc
 * 1982 to 1996**
 * 1997 to 1999**
 * 2000 to date**

Here's a youtube video that shows the demo from the VERY beginning:

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The Floating penny The reason why this was a redox reaction is not because the penny is made of copper but rather that it has a core of zinc and plated with copper. Therefore the reaction is due to both the zinc and copper in acid. Jen had made file indentations which helped to insure that both metals were exposed to the solution. In the reaction the zinc oxidizes to Zn2+ ion which dissolves. The copper however does not dissolve in Hydrochloric acid thus making the penny float. Zn (s) + 2H+(aq) à Zn2+(aq) + H2 (g) For more information see: [|Floating Penny Experiment]