Kitchen Chemistry
Introduction: Kitchen Chemistry
Experiment with small quantities of ingredients from your kitchen cabinets to explore basic chemistry: what does it mean when something mixes, dissolves, or reacts? Some of the combinations may be predictable, some surprising. What ingredients are responsible for the different results? Everyone will have different ingredients and this will make it interesting to share our results.
This workshop was designed for out-of-school-time educators as a family workshop (children with an adult present) but can be easily adapted to other educational settings. The activities are suited to remote learning since they use common materials, and not every participant needs to have the same ingredients. In fact, everyone having different ingredients will make it interesting to share results.
Facilitator Notes: The workshop helps ground some fundamental chemistry concepts in a very approachable way: by experimenting with familiar food ingredients. Participants will observe the ingredients closely, and the facilitator can help link participants' observations to chemistry concepts. Concepts include liquid and solid, and different properties of solids including crystals, grain sizes, etc. (See the glossary for basic explanations of chemistry terms.) Experimenting with mixing different ingredients brings in the ideas of mixtures, suspensions, solutions, emulsions, dissolving, density, chemical reactions, pH, and more. Don’t overwhelm the conversation with the technical terms — it is better to focus on the experiences with real materials, observations, and investigations. Introduce the chemistry vocabulary when it will help give a name to what participants are observing, or it will help explain what is happening on an invisible (molecular) level.
The outline is written assuming participants have little background chemistry knowledge. 440
Fundamentally the activity is about observation and encouraging participants to learn by working with the materials. As a facilitator you do not have to know all the chemistry involved — indeed food chemistry gets complex quickly, and few people could claim to understand all the chemistry involved. However, knowing some of the basic ideas can help you point out interesting phenomena, link observations to chemistry topics, and suggest potential further avenues for investigation.
Supplies
Be Safe: Use food ingredients only! (No cleaners or things from under the sink!) This activity assumes the adult member of each participant group is responsible for safety and modifying the activities to address any possible food allergy issues.
We will use small quantities of each ingredient (a few tablespoons at most). Don’t use anything too expensive -- like vanilla or spices.
Have participants gather supplies from their kitchen — one thing from your kitchen cabinet or refrigerator for each category below. At this point, participants should keep the ingredient in its bag, box, or bottle:
* One Liquid ingredient (for example, juice, vinegar, oil, etc.)
* One dry ingredient (for example, salt, sugar, flour, baking soda, etc.)
* A blue or purple vegetable or fruit (if they have one)
* Measuring spoons: ¼ teaspoon, 1 tablespoon (if not available substitute any small spoons)
* A couple of small spoons, stir sticks, or something to stir with
* A magnifying glass (if available)
* Dishcloth or paper towel
* Two or more small zip lock bags (if available), otherwise any clear containers (glasses, small jars, clear plastic containers, clean baby food jars, clear plastic egg carton from recycling, or other)
Be Safe: if using jars with lids keep them open! Some mixtures (such as baking soda/powder and vinegar will produce carbon dioxide -- a harmless gas (see glossary for more information). The gas needs a way to escape or it can burst the container.
Step 1: Gather the Ingredients
Have people gather their ingredients if this has not been done in advance.
Step 2: Investigate Your Dry Ingredient
As participants finish collecting their materials, have people start the first investigation:
Have each participant put 1/4 teaspoon of their dry ingredient into a zip bag (or other container) and investigate it.
Some questions are below, and you can use them on screen to help prompt the investigation.
Investigate your kitchen chemistry ingredient: Put ¼ teaspoon of your dry ingredient in a container.
* Look at it — how would you describe it? (Color, texture, shape?)
* Look as closely as you can (use a magnifying glass if you have one). What do you see?
* Rub a pinch between your fingers. What does it feel like?
* Does it have a smell?
* Does it make a sound if you shake it?
Step 3: Investigate Your Liquid Ingredient
Talk about exploring, observing, and being surprised by common food ingredients.
Then have participants take a second container and put in one tablespoon of their liquid ingredient. (1 tablespoon = 3 teaspoons)
Investigate the liquid ingredient using the same questions as above. 643