The Center for Environmentally Beneficial Catalysis (CEBC) hosted two separate hands-on activities for more than 500 area children at the 14th annual Carnival of Chemistry this November.
In one activity, dubbed “The Juice is Loose,” the color-changing power of purple cabbage was used to visually explain acid-base chemistry. When purple cabbage is soaked in hot water, pigments in the cabbage turn the water blue. This “juice” dramatically changes color depending on the pH of the liquid.
Children experimented with adding different household liquids to the cabbage juice. After adding lemon juice, one two-year-old girl exclaimed, “Pink – my favorite color!”
What happens if you blow through a straw into the cabbage juice? Kids discovered that their exhaled carbon dioxide changes the color of the juice from blue to purple.
“This indicates that carbon dioxide dissolves in water to produce a weak acid,” explained Griffin Roberts, CEBC graduate student. He added, “As atmospheric carbon dioxide levels rise, more and more of this gas will dissolve in the Earth’s oceans, decreasing the pH and disrupting the growth of plants and animals.”
CEBC’s popular “Touchable Bubble” activity was back by popular demand.
Mauricio Antezana, one of the CEBC graduate students assisting with the event, captured the attention of crowds of youngsters with this bubble activity (pictured at right). He made the bubbles by dropping dry ice in warm water. The foggy vapors were then funneled through a soapy solution.
“Dry ice is frozen carbon dioxide, and instead of melting, it changes from a solid to a gas,” said Mauricio.
Together, these activities help the public learn about carbon dioxide and the affects of this colorless, odorless gas on the environment.
One of the major research initiatives at CEBC is to reduce the carbon dioxide emissions of large-volume chemical manufacturing processes. The center is also exploring ways to use abundantly-available carbon dioxide to replace harmful solvents in industrial processes.
--Story by Claudia Bode