Cucumber Chemistry: The Drying Power of Dessicants
Substances that can absorb water from the environment can help keep products dry—or help dry out something that has gotten wet, like an electronic device. The small silica gel packets that you often find when you open a new product are used to help keep the product dry. The properties that make a silica gel packet work are properties you can find in other substances as well. There are even ordinary kitchen ingredients that can be used to absorb moisture and help to dry something out or keep something dry. Experimenting to see how effective certain ingredients are at absorbing moisture may even help you find ways at home to prolong the life of certain foods.
In this week's family chemistry activity, students use cucumbers and test substances like sugar and salt to see which ingredients do the best job of drawing moisture from the cucumber. How will the cucumber change after an hour? After a day? Which substance works best? How can you measure how effective the substance is at absorbing moisture? With a few slices of cucumber and some kitchen ingredients, families can experiment and observe firsthand what happens.
After this chemistry activity, families will better understand why a phone dropped in water is often put in a bowl of rice! But maybe there is something else you could use that would be equally effective? Rice is not used in this week's activity, but since a phone in a bowl of rice is a very common attempt to save a wet cellphone, you and your students might add one more cucumber slice to your testing and see how rice compares to the other ingredients.
- Cucumber Chemistry: Moisture Capture with Desiccants (science activity at Scientific American)
For other hands-on science projects that are related to similar science principles, see:
- Minding your Mummies: The Science of Mummification
- Yuck, What Happened to My Apple? How Food Wrappings Affect Spoilage