Its+a+Gas!

__**Rockets**__ media type="youtube" key="SW87Vj7RmWM?rel=0" height="480" width="853" One important characteristic of     gas is pressure. Increasing the amount of gas in a container can raise the pressure of a gas. In this activity, you will use the build-up of gas pressure to launch a filmcanister rocket. **Materials** File folder or card stock Blunt-end scissors Glue Empty film canister Double-sided tape Half of an effervescent antacid tablet Water Stopwatch NOTE: This activity can be messy and should be conducted outside.

1. To make fins for the rocket, trace the pattern below (four times) onto a file folder, or a piece of card stock. 2. Cut along the solid lines so that you make four fins. 3. Fold the fins along the dotted lines. 4. Place glue on each of the fins in the area marked “Glue here” in the picture above, and attach each of the fins to the film canister. Be sure to have the point of the triangle towards the closed end of the canister and to leave enough room to put the lid on the open end of the canister. 5. Fold the fins so they stick straight out from the canister.
 * Procedure**
 * Build the Rocket**

1. Ask your adult partner to help you select an appropriate area outside for the launch of your rocket. 2. Fill the canister half full of water. 3. Tape the half tablet of the effervescent antacid inside the lid of the canister using a piece of double-sided tape. 4. Close the canister, quickly place it on the launch area with the lid at the bottom, and take at least three big steps backwards. 5. The tablet should produce enough gas in the canister to pop off its lid, which will propel the rocket into the air. 6. Dissolve any unreacted pieces of the effervescent tablets by placing them in a bowl of water. Thoroughly clean the work area and wash your hands. 7. Record your experimental data
 * Fuel the Rocket**

Effervescent antacid tablets contain an acid and a base, similar to baking powder. When the acid and base are dry, they do not react, but when they dissolve in the water, they react to produce carbon dioxide gas. As the gas is formed, pressure builds up until, finally, the cap is blown off the canister and your rocket is launched
 * Where’s the Chemistry?**

__**Pop Rock Science**__ media type="youtube" key="-QiXePPTvBo?rel=0" height="480" width="853"

Pop Rocks are known as the exploding candy, and if you ate Pop Rocks as a kid, you probably remember the legend... if you eat Pop Rocks and then drink a soda, you'll explode. The Food and Drug Administration even set up a telephone hotline to assure anxious parents that the popping candy would not cause children to explode. While you can mark this one up as urban legend (in other words, it's not true), there is some interesting science behind the world famous popping candy.

Materials

 * A supply of Pop Rocks (the exploding candy might be a little difficult to find)
 * A 12 or 16 oz bottle of soda
 * A balloon
 * A narrow-mouthed jar

The Crush Test - Pop Rocks don't have to be mixed with a liquid to pop. Try crushing a few big pieces on the table using the back of a spoon and you'll hear the loud POP! Remember, the popping sound you hear comes from bursting the high pressure bubble of carbon dioxide. Crush a Pop Rock in your teeth and you'll hear the same cool popping sound of the gas escaping.
 * How Much Carbon Dioxide Gas is in a Packet of Pop Rocks?** - You'll have to waste a whole package of Pop Rocks for this experiment (or you can just learn from our results). Start by pouring an entire package of Pop Rocks into an empty balloon (a 9" balloon works well). You'll also need a 12 or 16 ounce bottle of your favorite soda. Open the bottle of soda and attach the balloon, but do not let the Pop Rocks fall into the soda just yet. After the balloon is attached, you can lift up on the balloon to allow all of the Pop Rocks to fall into the soda. Predict how big the balloon will get when the Pop Rocks mix with the soda. You might be surprised by what you see.

How does it work?

 * How are Pop Rocks made?** According to information from the manufacturer, Pop Rocks start like any other hard candy by combining sugar, lactose (milk sugar), corn syrup, and flavoring. These ingredients are heated to the boiling point and the hot sugar mixture is mixed with carbon dioxide gas under high pressure (about 600 pounds per square inch). The process causes tiny high pressure bubbles of carbon dioxide gas to form in the candy. When the hot candy mixture cools and the pressure of the gas is released, the hard candy shatters into tiny pieces of carbonated candy. If you look carefully at the candy under a magnifying glass, you'll see the tiny bubbles - each containing a small amount of carbon dioxide gas under high pressure (600 PSI). When the candy melts in your mouth, the 600 PSI bubbles of gas are released with a loud popping sound. Very cool! In the experiment with the balloon, mixing Pop Rocks with soda is a physical reaction - not a chemical reaction. The soda dissolves the candy and releases the small bubble of carbon dioxide gas from the Pop Rock. Believe it or not, most of the carbon dioxide in the balloon came from the soda. Dropping Pop Rocks into soda causes some of the carbon dioxide from the soda to escape. That's the real reason why the balloon inflates. So, will you explode if you eat Pop Rocks and drink soda? No... but you might get a pretty nice burp out of the deal.