Snowstorm in a Jar

There’s lots of cool science stuff going on here!

For starters, the water is more dense than the oil, so it sinks through the oil and sits at the bottom. Also, the oil and water are immiscible (un-mixable), so they will always separate back into separate layers.

The acrylic paint is water based, so it will mix with the water to make white water. If you used oil based paint (for example, blue would be lovely!), the oil paint would mix with the baby oil and make the oil blue.

On a side note, food colouring is also water based, so if you add it to your jar, it will mix with the water and will make your bubbles blue.

The Alka Seltzer has sodium bicarbonate (baking soda) and citric acid in it. When those mix with water they form bubbles of carbon dioxide which rise up to the surface through the oil. When the carbon dioxide is released into the air, the remaining water falls back down through the oil. (Why? Because water is more dense than the oil)

The carbon dioxide carries some of the water and paint mixture up with it. Since the oil and water are immiscible, these bubbles are easy to see in the oil. If we were doing this experiment without any oil, we’d basically have a fizzing jar and we wouldn’t be able to see those awesome little bubbles rising up and falling down again!