How to Make a Hydrogen Balloon
WHAT YOU NEED: funnel, 2 cups water, clean and empty wine bottle, rubber gloves, protective goggles, 3 tablespoons Crystal Drano (sodium hydroxide), aluminum foil (12-by-12 inches), balloon, string.
WHAT TO DO:
1. Working outdoors with adult supervision, use the funnel to pour the water into the wine bottle.
2. Wearing rubber gloves and goggles, carefully add the Crystal Drano into the bottle. Carefully swirl the bottle to dissolve the Drano.
3. Make twenty small balls from the aluminum foil (about 1/2 inch in diameter) and drop them into the bottle.
4. Stretch the balloon well and immediately place the neck of the balloon over the mouth of the bottle. Let it inflate as big as it can get. This takes about ten minutes.
5. If the solution doesn’t give off enough gas to fill the balloon, add more aluminum; if the glass gets too hot, you’ve used too much aluminum.
6. When the balloon is full, tie it off with the string. (DO NOT breathe the vapors from the bottle, and carefully dispose of the remaining solution in the bottle.
WHAT HAPPENS: A chemical reaction gives off hydrogen gas, which fills the balloon. Since hydrogen is lighter than air, the balloon floats.
WHY IT WORKS: The aluminum interacts with the lye in the Crystal Drano, causing the hydrogen molecules to separate from the oxygen molecules in the water.