Bottle Rockets

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Required Training	Required PPE
UC Lab Safety Fundamentals	Flame-resistant lab coat, safety glasses/goggles, hearing protection, nitrile gloves
Performers Required: 1
Equipment	Chemicals
Clean, dry 1 or 2 L soda bottles with caps	Methanol (CH₃OH)
Launch pad (small/medium iron rings on steel lab stand)	Oxygen (O₂), with regulator and tubing installed
BBQ-style butane lighter (≥ 6” long)

Procedure:

Add 1 mL of methanol to dry soda bottle. Typically the volume of a bottle cap is sufficient to get over 30 feet of clearance. Shake the closed bottle to disperse the methanol.
Fill the bottle with oxygen gas from a cylinder fitted with a regulator. Hold the bottle over the outlet of the regulator (set to ~5 psi) for ~30 seconds.. The demo can be performed immediately, but the effect will be greater if the bottle is allowed to sit at room temperature for at least 20 minutes. Do not store prepared bottle rockets for more than 24 hours, and keep them out of direct sunlight and away from heat or ignition sources.
Before the demo, quickly loosen the cap and allow any excess methanol to drain out, and then re-tighten the cap.
To mount the bottle on the launch pad, simply place the bottle cap-side down in one of the iron rings and point away from the audience. The bottle rocket should never be pointed towards other performers or the audience.
Ensure you are wearing hearing protection and that the audience has been warned to cover their ears before proceeding. Unscrew the cap from the bottle and hold the flame from the butane lighter near the opening. Keep your hand to the side of the bottle rocket, and never place anything directly above or below the bottle. Once ignited, there will be a loud noise and the bottle rocket will quickly launch ~10-100 feet into the air, largely depending on ambient temperature.

Clean-up: None required, except for retrieving all bottles and caps for recycling.

Hazards: Methanol is toxic and highly flammable; it should be kept away from heat or ignition sources, especially when in an oxygen-rich environment such as a prepared bottle rocket. Methanol burns with an almost invisible blue flame, which is extremely difficult to see in bright light. Launching the rockets produces heat, fire and a loud noise, and the bottle is launched upwards with great force. Hazards include thermal burns from the fire, hearing damage from the explosion, or physical injury from being hit by the launching bottle.

Principle: The combustion of methanol and oxygen produces carbon dioxide (CO₂), water vapor, and heat. These hot gases quickly expand and exit the bottle through the neck, creating thrust that propels the bottle upwards.

Notes: Methanol has a flash point of 11 °C (52 °F), and the vapor pressure increases dramatically with increasing temperature. If this demo is to be performed during the winter months, the bottle rockets need to be kept above this temperature in order to ignite, and kept close to 20 °C (68 °F) in order for there to be enough fuel in the mixture to get a decent launch. This can be achieved by placing room-temperature bottles in an insulated bag, only removing them one at a time as they are launched. If it is sunny outside, the bottles may be warmed by placing them in direct sunlight for no longer than 5-10 minutes, or until they are just barely warm to the touch. Under no circumstances should the bottle rockets be heated beyond this point, as this could cause them to burst or ignite in an uncontrolled fashion. 2 L bottles will become slightly warped from the heat of the launch, and should not be reused; smaller 1 L bottles hold up significantly better and can usually be reused 2-3 times. Disposable water bottles are not durable enough for this demonstration, and should not be used.