The first outreach activity was carried out at Den Grønne Dal, Vanløse, Copenhagen, Denmark, on 16th November, 2013. I explained concepts such as Mineral, Precipitation, Dissolution, electromagnetic spectrum, Mie scattering phenomenon and pH indicators to the participants during the outreach activity. These concepts were illustrated with a real case, Río Celeste in Costa Rica. It was an interactive activity where we tried to understand our main question: what causes the emerald green color in the water of Río Celeste if this river is formed by mixing the water of two colorles rivers, which are Quebrada Agria and Río Buenavista. We compared the chemical composition of the water of the three rivers and we tried to find out if there is correlation between the chemical composition of the elements and the coloration of the waters. Then, the participants did experiments using red cabbage juice as a natural pH indicator, so they determined the pH of vinegar, chlorine and soap by comparing the color change with the pH scale for natural indicator. Afterwards, we had snacks, drinks and friendly talks.
Interactive activities during the outreach:
Trying to find a correlation between the chemical composition with the coloration of the water:
pH determination using red cabbage juice indicator:
Determination of pH of some liquids by comparing with pH scale for natural indicator:
Next time if you are going to cook red cabbage, remember keeping its juice, and use it as pH indicator at home!