This week's experiment is a fun trick that is useful too. How can you pour a glass of soda without getting a glass that is half soda and half foam?
To find out, you will need:
- 2 glasses
- ice
- carbonated soda
Take some ice straight from the freezer. Put a few cubes into a glass and pour in some carbonated soda. You will get lots of foam and fizz.
Next, put some more ice into the second glass. This time, fill the glass with water and then pour the water out. Pour in the carbonated soda and observe. This time, there is much less foam.
What is happening? What is the difference between ice fresh from the freezer and "wet" ice? Comparing the surfaces of the two, the wet ice is much smoother. The fresh ice has a surface with lots of rough spots and irregularities. Why would this make a difference?
The carbonated soda is a liquid with a gas dissolved in it. This gas (carbon dioxide) easily comes out of solution, forming bubbles. Rough surfaces give the gas bubbles a better place to form, producing more foam. You can see this by trying another rough surface, some grains of sugar. When you sprinkle the grains of sugar into the soda, it foams up. If you dissolve the sugar in a little water, you can add the solution without the same level of foam. You could do the same thing with a little salt, but then you would not want to drink the soda afterwards. It would be a shame to let it go to waste. You would not believe how much soda I drank while researching this one. Sometimes we have to make sacrifices in the name of science.
Have a wonder-filled week.
