How many bubbles in coke

Today, bubbles in soda and bubbles in teakettles. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them. A scientifically savvy friend stopped me yesterday to ask if I'd ever done a program on champagne bubbles.

He figured there must be more to them than meets the eye. And, indeed, there is. We tend to think that bubbles in liquids should all be pretty much the same thing. In fact, bubbles that rise from carbonated liquids are completely analogous to those in boiling water, yet they're the result of radically different actions. Both are formed by something flowing through the liquid.

But what does that mean? Liquids are supposed to do the flowing; and I'm asking you to picture something passing through a liquid while it just sits there. One of those somethings is heat. The bubbles are made from a gas called carbon dioxide. The soda pop company puts the carbon dioxide in the soda to give it that special fizz.

You can see some of this carbon dioxide fizz, bubble, and pop in this activity with soda pop! Bubbles form on the different objects because of the carbon dioxide gas in the soda pop.

Even though the straw, popsicle stick, and other objects might seem smooth, they actually have many tiny little bumps, indentations, and scratches where the carbon dioxide molecules attach. Once the carbon dioxide molecules have a surface to attach to, the molecules build up and form bubbles.

Carbonated beverages are produced by dissolving carbon dioxide in liquid, typically under high pressure. Popping open a can or bottle of the liquid reduces that pressure, releasing the carbon dioxide in the form of bubbles.

Enzymes in the mouth convert the carbon dioxide into carbonic acid. It turns out the medication blocked the enzyme that converts carbon dioxide into carbonic acid. Still, popular belief continued to hold that the bubbles were primarily responsible. To settle the debate, scientists at the Monell Chemical Senses Center in Philadelphia took advantage of the inability of bubbles to form above a certain pressure level.

To make a new bubble, the molecules in the carbon dioxide and the drink move around and get organised to make a surface between them. Less new surface needs to be made if the bubble starts against the edge of the glass.

This uses less energy and means new bubbles usually start here. This is also why small bubbles tend to stick to the glass. More gas will join the small bubble, as it takes less energy to escape into a bubble to make it bigger than make a new one. Eventually, the bubble gets big enough that it will float to the top of the drink.

This happens when the bubble is still smaller than a grain of sand. When you blow through a straw to make bubbles, the same forces are acting on the bubbles as before. But the bubble is stuck to the straw all round the edge of the hole. This is why they are larger than the bubbles that form on their own in a drink. Try to find a thinner straw to see how small a bubble you can make.