dancraisin

Materials:
7 to 8 raisins
7 to 8 small pieces of open shell macaroni
7 to 8 dried black-eyed peas
one jar, empty
one large beaker with yellow liquid (liquid consists of water saturated with baking soda with a few drops of food color added)
one small beaker with red powder (powder is baking soda with food color added)
one small beaker of blue liquid (this liquid is vinegar with food color added)
one stir stick
one Styrofoam bowl
paper towels

Procedures:

1. Place the empty jar in the middle of the Styrofoam bowl. (This is to catch any spills.)

2. Pour the yellow liquid into the jar. Add the red powder to the yellow liquid. Stir. Add the raisins. Observe what (if anything) happens and note your observations.

3. Slowly and smoothly add the blue liquid. DO NOT pour rapidly. Observe what (if anything) happens and note your observations.

4. Add the open shell macaroni and dried black-eyed peas. Observe what is happening and note your observations.

Note to Teachers:
My results:

The yellow liquid is salty and has particles floating in it. After adding the red powder the yellow liquid turned orange. It is opaque and thin. It smells slightly sweet** but is still salty to the taste. There is more sediment on the bottom. One raisin floated on the top briefly. After stirring, all the raisins settled on the bottom. I didn�t hear fizzing, hissing or any other sounds from the beaker. After adding the blue liquid, everything began fizzing. The fizz can be seen and heard. The fizz on top looked a little green. The raisins began floating to the surface, waited a second or two, flipped over and sank to the bottom. Bubbles surround and adhere to the raisins on the bottom of the jar. The color of the mixture is semi-clear until it is stirred up. The color is more yellowish than orange. There was still lots of sediment on the bottom. Particles are coming off the raisins.

After adding the pasta and peas, the pasta initially stayed on the bottom. The peas reacted just like the raisins, coming up to the surface, turning over and sinking back to the bottom. It looks kind of like the bubbles in boiling water. The raisins looked fatter and seem to be slowing down on the rise and fall activity. The pasta will rise but not turn, just touches the top of the liquid and fall back down. There are larger bubbles rising in the mixture. Now the pasta is acting like the raisins and peas. The noodles are still hard, the raisins squishy like fresh raisins. More pasta, raisins and peas are staying on the top. Bubbles surround all pieces on the bottom of the jar.

My conclusion:

The red powder is baking soda. The yellow liquid is baking soda saturated water. The blue liquid is vinegar. Mixing the vinegar and baking soda creates carbon dioxide gas. The carbon dioxide gas adheres to the objects in the jar causing them to float to the surface, where the contact with air pops the bubbles on the surface. Due to the gas bubbles attached to the bottom of the object, the object turns over, these bubbles burst and the object sinks back to the bottom of the jar. Here more carbon dioxide gathers on the object and the cycle begins again. The surface of the object plays an important part in the �boiling� process. A rough surface with ridges will allow more carbon dioxide bubbles to adhere to the object than will a smooth surface. When a base (baking soda and water) mixes with an acid (vinegar) a chemical reaction occurs creating carbon dioxide gas. This forms bubbles in the mixture and when rising to the top there are so many bubbles that burst simultaneously and almost simultaneously the sound created is a hissing fiz. This also creates a foamy surface. Due to the speed the bubbles rise immediately after the base and acid mix; however, the foam is very short lived.

**One team member mentioned the mixture looked like Tang. When we smelled it immediately after this remark, we all got a slightly sweet odor. This could be from the power of suggestion but it did not alter the results.