Dr Dot's Lava Lamps

https://www.youtube.com/watch?v=8xJlEuGBPRw

Equipment

1 Glass Jar

Cooking oil

water

food colouring

dropper from medicine/pippette

fizzy tablet, e.g. Alka-Seltzer or pure vitamin C tablet

PPE: lab coat or apron, safety goggles, gloves

*Personal Protection Equipment is not essential for this experiment, as we do not work with harmful chemicals, but it is good practice. If working with chemicals, you MUST wear at all times, including a mask.

Steps

1. Wash your hands, put on your PPE (lab coat, safety goggles, gloves), and clean your work surface with antibacterial spray.

2. Add oil to your jar; about three-quarters full will do.

3. Then add in some water. Do not fill the jar.

4. Add a few drops of food colouring using your pipette.

5. Drop in a fizzy tablet. You can reactivate the experiment later by popping in another tablet to the mixture!!! Simple right?

Observations

The oil floats to the top of the water. When the fizzy tablet is added, bubbles go from large to small, bringing the coloured water up through the oil layer and back down again.

Explanation

Oil and water are IMMISCIBLE, meaning they are liquids that do not mix. This is because water is more dense than oil. Water is also POLAR meaning that the water molecules have a positive and negative end and can attract each other, but not oil.

There is a chemical reaction between the acid in the tablet and the water, creating bubbles of the gas, carbon dioxide.

Challenge!! Can you think of any miscible liquids? Liquids that do mix? Can you think of any other liquid besides water we could use for this experiment? What other powders could you use?

Lava Lamps!!

Did you like what you saw? This is one of many experiments that Dr Dot does. Follow her on YouTube, and join her fantastic Online Science Club where you can have a conversation with other members, post your experiments, complete confidence boosting courses and attend monthly Zoom sessions!!