Have you ever seen oil on puddles in the street after a rain? Have you ever wondered why oil and water don’t mix? Let’s experiment and try to understand, with this ‘Oil and Water Don’t Mix Experiment'
You will need:
- A jar with a lid
- Vegetable oil
- Food coloring
1 Fill the jar half-way with water.
2 Add a drop or two of food coloring.
3 Fill the other half of the jar to the rim with vegetable oil.
4 Screw on the cap.
5 Set the jar down and observe. The jar is layered with the oil on the top and the water on the bottom, because the water is heavier than the oil.
6 Next turn the jar, tipping it from side to side. Notice how the oil and water create waves.
The science behind the ‘Oil and Water Don’t Mix Experiment:’
When two liquids like oil and water separate into layers it’s said that the two liquids are immiscible –they are not capable of mixing. This explains how animals living outdoors even in very wet weather will not get wet. This is because their fur coats are very oily. Have you ever taken a salad dressing out of the refrigerator and noticed that the ingredients seem to have separated?
Oil and water are two ingredients that refuse to mix together. Why?
Water is a compound made of millions upon millions of tiny little molecules, each with a positive charge at one end and a negative charge at the other.
These types of molecules are called “polar molecules.” The reason water sticks together, is because the positive charge of one end of a molecule will attract the negative end of the molecule next to it, and so on! Many other molecules, such as the ones that make up salt or vinegar, are also polar molecules; which is why they mix with water so easily. The molecules that make up oils are also charged, but its positive and negative charges are spread out more evenly. This makes it a “non-polar molecule.” Because the water molecules are unable to find a negative charge to connect their positive ones to, they can only mix with non-polar molecules for a very short time – such as when you shake up that salad dressing – before it separates again!
Now that we know about oil, let's get cooking with this Chanukah Doughuts Recipe.
As seen in Joy of Kosher with Jamie Geller Magazine (Bitayavon - Winter 2011) - Subscribe Now.