Emulsion: is a mixture of two or more liquids that are normally nonmixable.
Density: the condition of having parts that are close together; the amount of something in a specified volume or area.
Items you’ll need for your experiment:
- Small soft drink bottle or a container that has a lid that screws on tightly
- Food coloring (We didn’t have any liquid coloring but we did have Amarillo powdered, for our Cuban yellow rice dish 😉 )
- 2 tablespoons of cooking oil
- Dish washing liquid (one or two squirts)
- Add a few drops of food coloring to the water.
- Pour about 2 tablespoons of the colored water along with the 2 tablespoons of cooking oil into the small soft drink bottle.
- Screw the lid on tight and shake the bottle as hard as you can.
- Put the bottle back down and have a look, it may have seemed as though the liquids were mixing together but the oil will float back to the top.
We observed oil and water do not mix! Water molecules are strongly attracted to each other, this is the same for oil, because they are more attracted to their own molecules, they just don’t mix together. Oil and water separate and the oil floats above the water because it has a lower density.
Now add some dish washing liquid and shake it up. The soap is attracted to both water and oil, helping them all join together and form something called an emulsion.
Have fun trying to make oil and water mix but remember to screw on the lid tightly 🙂