Science Club - Lava Lamps

Before half-term, the Science club had the delight to create Lava lamps with a Valentine's Day twist. Students learnt about density and the properties of liquids. Students created their lamps from a mixture of water, oil, alka seltzer tablet and of course, pink food dye!

By creating their lava lamps, students learnt that certain liquids would rather bond together molecularly with like molecules than with non-like molecules. This type of liquid is known as an immiscible liquid.

Oil is less dense than water, so it remains on the surface of the coloured water. When you add alka seltzer tablets to the water, an endothermic chemical reaction starts which gives off carbon dioxide gas. The carbon dioxide gas is less dense than the mixture, but as the gas rises, some of the coloured water forms around the gas, creating carbon dioxide bubbles.

Then, when the gas rises to the top of the oil and into the air, the denser water drops back down to the bottom of the container. This cycle will continue until the Alka Seltzer tablet stops reacting!

Huge thanks to sixth-form students Kezia and Ibrahim for their support for the club