How to Make Hydrogen Balloons

Kids love scientific experiments with actual results, and there is almost no other with such exciting results as making hydrogen-filled balloons. With a little preparation, this experiment is sure to be a hit. This easy-to-do project can be done with very little equipment and a couple of household items. Even very young children can learn that hydrogen is lighter than air by watching it being made and then having the fun of seeing the proof.

Things You'll Need

• 2 large flat-bottomed glass flasks
• 1 one-hole large silicone flask stopper
• 1 two-hole large silicone flask stopper
• 3 8-by-¼-inch glass tubes
• 4 3-by-12-inch strips of aluminum foil
• 12 inches of ¼-inch rubber tubing
• 2 tbsp. lye
• Water
• Round 12-inch balloons

Instructions

How to Make Hydrogen Balloons

1. Insert one of the glass tubes into the one-hole stopper. The stopper should be placed approximately in the middle of the tube.

2. Slide a second tube into one of the holes in the two-hole glass stopper so that the tube is about in the middle of the stopper. Slip the last tube into the remaining hole until it is about ½ inch from the bottom of a flask.

3. Fill one of the flasks with about 2 inches of water and seal it with the two-hole stopper.

4. Attach the rubber hose to the glass tube that extends into the water, and connect the other end of the hose to the glass tube on the other stopper.

5. Tear off and loosely crumple four strips of aluminum foil and place them in the open flask.

6. Blow up a balloon to stretch it so that the hydrogen will go into it more easily. Put the balloon onto the glass tube.

7. Place 2 tbsp. lye into the open flask and add about 2 inches of water.

8. Cover the flask with the stopper that is attached to the hose and connected to the other flask.

9. Hold on to the neck of the balloon as the hydrogen gas collects in it. When it is full, take it off the glass tube and tie it off so that the hydrogen doesn't escape.

Tips & Warnings

• Compare the differences between a balloon filled with air, one filled with helium and one filled with hydrogen

• This is not an experiment for young children to perform, but they can watch from a distance. Extra care must be given when handling lye. If you are going to explode a balloon filled with hydrogen, make sure you do it in a large open area with nothing close by that might catch fire.

Resources

• Source for lab supplies