The Amazing Mystery POP Bottle

The experiment is built on the idea that some chemical reactions create gas as a product (an outcome) of the reaction. If a gas generating reaction is carried out in an enclosed space, the result can be dramatic, as we saw on television. Doing this experiment is not very hard, but because something gets shot out of the bottle, it is important that safety be the first thing to be considered. Never shoot a bottle made for this experiment at somebody...even if the cork or stopper doesn't move very fast it may have small amounts of chemicals on it and though the chemicals used are relatively safe, any chemical in a persons eye, for example, could cause serious injuries.

How to build the Amazing Mystery POP Bottle:

  1. First, you need a bottle that has a cork or rubber stopper that fits snuggly into its openning. Here in Milwaukee we can get corks or stoppers at a science surplus store - and if you're looking at this page from outside Milwaukee, I included a link to science suppliers on-line below.
  2. You also need some citric acid and some baking soda. If you can't find citric acid cream of tartar will work too.
  3. You need to cut a straw to be about half the height of your bottle and plug one end of the straw with modeling clay - then fill the straw with water.
  4. To assemble the pieces put about equal amounts of baking soda and citric acid in the bottom of your DRY bottle (it won't work if it isn't dry). Then carefully put the straw with the water in so that the water stays inside the straw until you're ready. Put the stopper in the top of the bottle and you're ready to go. If you want to make it a "mystery" bottle, cover the bottle with foil before you start to build it.
  5. When you are ready to show your creation, all you need to do is hold the stopper in place. Tip it upside down once and set it down. Wait for the reaction to take place and the stopper will shoot off in a short period of time. If you don't seal the stopper up, the gas generated may leak out instead of shooting the stopper, otherwise this science trick works almost every time.

 

How does it work?

The chemical name of baking soda is sodium bicarbonate. The bicarbonate part of this chemical is the important part that makes the reaction happen. It is an example of a base, which can react with an acid. When it reacts with an acid, carbon dioxide gas is generated. Citric acid is the chemical that provides the acid, but when it is a solid the part that makes it an acid cannot get "free" to react. By adding the water (from the straw) when the bottle is tipped upside down the reactive part of the citric acid (a hydrogen ion - present in all common acids) reaches the bicarbonate part of the baking soda and the reaction quickly generates the gas - causing the top to pop off.

Links

What is Cork? - if your stopper is cork, you might wonder what it is...

What is rubber - if your stopper is rubber this page can help you know how rubber is made.

Science supplies on line - if you need to buy science supplies over the net there are a few places - here's one.