By Penny Carmichael, on 17 February 2012
Last Tuesday brought to the Chemistry department a group of 20 inquisitive Year 9 students and their parents for a CO2 workshop. The afternoon aimed to let these students explore the properties of carbon dioxide inside a lab and inform them how dangerous this molecule can be.
Students and parents alike split into groups and began experimenting with a bowl of dry ice, a bottle of bubbles and the glove they had been given. Aiming to demonstrate the properties of carbon dioxide a group of volunteers lead experiments including putting dry ice into a lab glove to watch it expand as it turns from a solid into a gas, blowing bubbles over the bowl of dry ice to demonstrate the changes in density and finally allowing dry ice to melt on a paper towel to show that CO2 is never a liquid- the paper towel never gets wet! After a tentative start the students really began to grasp the theory behind the experiments and a couple even came up with their own experiment by releasing the CO2 gas from the glove into a stream of bubbles to see if they sank.
The experiments ended with a display to the group of how carbon dioxide acidifies an alkali solution via the simple act of adding dry ice to a gigantic test tube of water with indicator solution. This reaction captivated its audience as the addition of the ice caused the water to bubble and smoke whilst the solution green to reddish orange in colour.
Our afternoon ended with a talk from Dr David Rowley, who built on the group’s existing knowledge of global warming, explaining why Earth is the best planet for our survival and calculating the Earth’s temperature. Analysing atmospheric CO2 levels from the last 10,000 years and answering questions such as “why is the sun yellow?” Rowley outlined correlations in the rise of carbon dioxide and fossil fuel use, as well as the effect this has had on the Earth’s average temperature. Although so far these temperature increases have been small, can mankind really want to find out what a further increase could do? After all, prevention is always better than cure.