What's an easy place to find a ton of everyday, unintentional science experiments? You guessed it... the kitchen. The examples of chemistry at work in baking a simple cake alone are endless. Which leads us to Wacky Cake a.k.a. 1-2-3 Cake. (What better way to peak a middle schooler's interest than through their taste buds??)
note: this demonstration will require either access to an oven at school (Home-Ec. lab or maybe bribe the cafeteria workers?) or you baking the cake ahead of time at home and then pulling a "cooking show" and pulling that out with an Abracadabra! after you mix the ingredients.
Lesson: Tasty Chemical Reactions
Wacky Cake is a cake made with only 8 ingredients: flour, sugar, baking soda, salt, vinegar, vanilla, oil, and water. The interesting part is how the ingredients are added. You have to mix the dry ingredients then make three "craters" in the mix so that the wet ingredients can be isolated as you add them. But why? Consider the chemistry!
- Teaching Op.:
- Have the students discuss why it would be necessary to add the wet ingredients in this way. Then, have them hypothesize what would happen if they were to ignore the directions and mix everything all at once.
After your class discussion begin your lesson with a few vocabulary words: chemical reaction, chemical property, and physical property (noting the differences between the latter two) and going over the signs that a chemical reaction has occurred:
- Change of color
- Formation of gas
- Formation of precipitate
- Change of temperature
- Energy produced (light emission, etc.)
Go ahead and make the cake! Make sure to have the students note any signs of a chemical change occurring!
Ingredients
1 1/2 Cups flour + 3 Tablespoons
1 Cup white sugar
1 tsp. baking soda
1/2 tsp. salt
1 tsp. white vinegar
1 1/2 tsp. pure vanilla extract
5 Tbsp. vegetable oil
1 Cup water
Directions
Preheat oven to 350 degrees F.
Mix first 4 dry ingredients in a greased 8" square baking pan. Make 3 depressions in dry ingredients - two small, one larger. Pour vinegar in one depression, vanilla in the other and the vegetable oil in third larger depression. Pour water over all. Mix well until smooth.
Bake on middle rack of oven for 35 minutes.
VANILLA CRAZY/WACKY CAKE RECIPE:
Ingredients
1 1/2 Cups flour + 3 Tablespoons
1 Cup white sugar
1 tsp. baking soda
1/2 tsp. salt
1 tsp. white vinegar
1 1/2 tsp. pure vanilla extract
5 Tbsp. vegetable oil
1 Cup water
Directions
Preheat oven to 350 degrees F.
Mix first 4 dry ingredients in a greased 8" square baking pan. Make 3 depressions in dry ingredients - two small, one larger. Pour vinegar in one depression, vanilla in the other and the vegetable oil in third larger depression. Pour water over all. Mix well until smooth.
Bake on middle rack of oven for 35 minutes.
