Soda Can Shake-up Have you ever wondered why shaking a soda results in a great explosion? email to friend
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Have you ever wondered why shaking a soda results in a great explosion when it’s opened? What causes a 2-liter bottle of soda to go flat? Is there anything that can be done to keep fizz in a bottle of soda? Get ready to uncover some amazing soda secrets that will change your soda drinking habits.

Since the fizz in the soda is actually dissolved carbon dioxide gas, the goal is to keep as much of the gas in the bottle as possible. Soda fizzes when dissolved carbon dioxide gas is released in the form of bubbles. At the bottling plant, carbon dioxide molecules are forced into the soda in an amount that is greater than would ordinarily dissolve under atmospheric conditions. As soon as you open the bottle, most of the excess gas escapes into the room – that’s a given! So, it’s your job to find a way to keep the remaining gas in the liquid.

Materials

Cans of unopened soda. It’s best to practice with clear liquids! Try club soda.

IMPORTANT: Diet soda does not work... you'll learn why later.

Experiment
Video

Vigorously shake a sealed can of soda.
Invite a dinner guest to immediately open the can! Of course, most sane people will refuse the offer.
With a little science know-how, you’ll be able to open the can without spilling a drop. The secret is to use your finger to snap the side of the can. This action dislodges the bubbles attached to the side of the can and they float to the top. When the can is opened, the gas simply escapes. As you will soon discover, tapping the top of the can does nothing.

How does it work?

Shaking the unopened can of soda causes bubbles of carbon dioxide to line the inside walls of the can. When you open the can, the pressure in the can goes down and the volume of each bubble goes up (Boyle’s Law). The quickly expanding bubbles force the liquid that rests above it out of the can.

Additional Info

Most people have learned to tap the top of the can before opening it. Scientifically speaking, THIS DOES NOTHING! However, tapping the side of the can knocks bubbles off the bottom and sides of the can, at which point they rise to the top. The trick is to dislodge the bubbles from the sidewalls and bottom of the can so they can float to the top of the can (because gas is lighter than liquid) and there is only a small amount of liquid blocking their escape when you open the can. Remember, SNAP the SIDE instead of tapping the top.