Things You'll Need
Instructions
Pour 20 mL of dilute hydrochloric or muriatic acid into a glass jar or beaker, or dissolve five sodium hydroxide pellets in 20 mL of water.
Pour 20 grams of granular zinc or six to eight pennies (dated 1982 or later) into the jar or beaker. If you are using the sodium hydroxide solution, use 0.3 grams of aluminum foil or tin can pieces instead of zinc or pennies.
Attach the mouth of the balloon over the neck of the bottle or beaker and wait for it to fill up with hydrogen gas.
Remove the balloon from the beaker gently and tie a knot in the bottom to hold in the gas.
Release the balloon and watch it rise to the ceiling.