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How to make a medicinal lava lamp

Andy Parsons walks us through the making of a medicinal lava lamp, and how to dispose of the completed lamp safely.

What ingredients do you need?

As well as the active ingredients contained within a single pill or capsule, there are inactive substances called fillers and flavourings, and also buffers to maintain the optimal pH at which the active ingredients will be effective.

The following ingredients will be required:

  • Alka-Seltzer tablets
  • A selection of food colourings
  • Cooking, olive or vegetable oil

The following items will be required:

  • A tall, clear glass

Ensure that you read through all of the instructions before beginning the experiment to ensure that you understand exactly what will happen at each step.

Step 1: Measuring

Fill approximately one-fifth of the glass with tap water.

Fill the remainder of the glass with cooking or vegetable oil. Ensure to leave a small gap between the oil level and rim of the glass as some “foam” may be produced.

If you wish to add any food colouring for an enhanced effect, then do so now. Different quantities of food colouring will produce different shades of the relevant colour.

Step 2: Adding the active tablet

Take your Alka-Seltzer tablet and drop it centrally into the glass. It should sink to the bottom of the glass and after a few moments bubbles should begin to form.

Repeat the experiment with different shades of food colouring, or alternatively different liquids in place of water. Do different temperatures of water produce different results? Will crushing the tablet into smaller pieces produce more bubbles? If cabbage juice is used in place of the food colouring, why is there a change of colour?

Be creative, add a backlight to create a true “lava lamp” effect or try dropping in small pieces of glitter to see what happens.

How to dispose of a lava lamp safely

Dispose of the completed lava lamp safely. We strongly advise to not consume the “lava lamp” at any stage of the experiment.

Dispose of the lava lamp down the sink, washing equipment thoroughly with cold water, once complete. It may be necessary to use warm water to wash away the oil (even though we normally use cold water to wash up after an experiment).

This article is from the free online

Exploring Everyday Chemistry

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FutureLearn - Learning For Life

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