Editing Bouncing Raisins

{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right"
| [[Chemistry]]:
| Density, Decomposition Reactions
|-
| Grade Range:
| [[Elementary School]]
|-
| Format:
| [[Hands-on]]
|}

A twist on the classic "Baking Soda and Vinegar Volcano" experiment, this will help students look at the reaction closely, and see more than just a foamy explosion. This demonstration is easy to run, and after initial setup you can let it run, only adding more reactants as needed throughout an entire science night!

== Materials ==

* Raisins
* Vinegar
* Baking Soda
* Clear Container (Graduated Cylinder, Beakers, Large Bowl, etc.), able to hold at least 500 mL

== Safety Precautions ==

Please read the Liquid Chemical and Dry Chemical sections of the [[Demonstration Safety]] page before performing this demonstration.


== Demonstration ==

# Set out your container, and first pour in your vinegar, filling it a third of the way. Then add your baking soda, being careful to not add too much at one time. Otherwise, you'll have a mess!
# As it bubbles, drop in 6-10 raisins. After the initial reaction, the solution will still bubble slowly, and students can come up to see the raisins bouncing!
# If the reaction slows too much to continue, add more vinegar or baking soda. If you see a lot of baking soda in the bottom, only add vinegar. Likewise, if there is very little or no visible baking soda, add more of it.


== Why This Works ==

We are all pretty familiar with the Baking Soda and Vinegar reaction: It is a decomposition reaction, which generates Carbon Dioxide gas:

NaHCO<sub>3</sub>(s) + C<sub>2</sub>H<sub>4</sub>O<sub>2</sub>(aq) ---> Na<sup>+</sup>(aq) + C<sub>2</sub>H<sub>3</sub>O<sub>2</sub><sup>-</sup>(aq) + H<sub>2</sub>O(l) + CO<sub>2</sub>(g)

Some of the gas that generates tries to stay in solution, but will come out of solution if it is able to collect onto something. The raisins do just that! Since the raisins have a lot of surface area (with the many wrinkles and gaps), they provide a spot for the bubbles to collect onto. When they do, they make the raisin a little more ''Buoyant''. In other words, because the raisins have a lot of gas collecting on them, they will start to float! Once they reach the surface, however, some or all of the bubbles will pop, and the raisin will lose that buoyancy and sink back to the bottom. This will repeat over and over again, as long as there is enough dissolved gas to collect on the raisins.

== Additional Information ==

* This demonstration pairs well with the [[Density Rainbow]] and the [[Exploding Soda]]