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Hands-on Chemistry at Techniquest

4 August 2011

Year of Chemistry Logo

Self-inflating balloons, multi-coloured markers and amazing red cabbage were just three of the hands-on experiments at Techniquest on Saturday 23rd July.

As part of Techniquest’s International Year of Chemistry celebrations, Cardiff School of Chemistry, along with the Royal Society of Chemistry (RSC), encouraged visitors to try some chemistry. The team, consisting of Dr James Redman, Dr Joel Loveridge, Dr Emma Carter, James Pritchard, Bruce Rogers and Dr Dayna Mason, kept crowds engaged and entertained with a variety of hands-on activities and experiments.

Fig 2

One of the most popular activities was paper chromatography – using filter paper and water to separate the colours of marker pens. Children of all ages were delighted to see the lines of black, brown and green become smudges of orange, pink and blue. Many visitors returned to the stall to pick up their rainbow masterpieces and take them home.

Another hit was the red cabbage chemistry. The juice of a red cabbage can be used as an indicator to show whether something is acidic or alkaline. In a neutral solution, red cabbage juice is purple, in an acid it turns pink, and in alkaline solutions the juice becomes green. Visitors to the stall investigated the acidity of common household products by adding solutions to red cabbage juice. A closer look at colours was possible with the use of the UV-Vis spectrometer, part of the Spectroscopy in a Suitcase kit.

Dr Dayna Mason demonstrates spectrometry

Although we breathe out carbon dioxide, many people haven’t seen carbon dioxide in its solid form. At normal pressures, carbon dioxide changes directly from a solid (at ‑78ºC) to a gas (ie. it sublimes). We used this to make self-inflating balloons. Gases take up much more space than solids, so we put a little solid carbon dioxide into a balloon (or a latex glove), tied it off and then got someone to shake it - the balloon appeared to inflate itself.


Although it was a busy day, the team never lost their smiles as they engaged with approximately 300 children and 90 adults. Jane Young from Techniquest said of the day: 

'I am writing to thank you and your volunteers for making such a marvelous contribution to our Colourful Chemistry launch on Saturday. Your stand was really fantastic and every time I passed there were so many people enjoying themselves. I am sure that you fired up a lot of children's interest in chemistry by making it so accessible. Please pass on my heartfelt thanks to all the team who worked so hard to make the day such a success.'

Dr Joel Loveridge and James Pritchard show the amazing properties of carbon dioxide

The activities and experiments are based on resources developed by the RSC. If you’d like more information about what we did, please contact Dr Dayna Mason.