INTRODUCTION: We all love a good chocolate chip cookie. They are an amazing combination of sweet, just a tiny bit of salt, a little bit of crunch and nice, rich gooey chocolate. But did you know that making chocolate chip cookies involves a lot of science?
All in one cookie, you will see chemical changes and physical changes. In this lab you will do just a little bit of work, observe these changes, learn about changes of states then enjoy a well deserved, nice, hot gooey cookie!
PURPOSE: To observe physical and chemical changes as well as changes of state in the process of baking a chocolate chip cookie.
MATERIALS: Pre-made chocolate chip cookie dough, baking oven set at 350 degrees, hot pads, oven mitts, spatulas, “The Chemistry of Cookies” video by Stephanie Warren
PRE-LAB QUESTIONS:
1.
What is the definition of a PHYSICAL CHANGE? Give five examples.
2.
What is the definition of a CHEMICAL CHANGE? Give five examples.
3.
What are the three most common states of matter?
PROCEDURE:
1.
Wash your hands and clean your work surfaces and any utensils you will be using.
2.
Obtain an un-baked cookie from your teacher.
3.
Determine the pre-baked density of the cookie by finding its mass and using the volume that will be given to you. List this in the data table.
4.
Note your pre-baking observations about the unbaked cookie including its approximate temperature (cold, warm, hot), color, shape, texture, smell, and any other things you notice about the unbaked cookie. Note these changes in the data table.
5.
Place your cookie on the cookie sheet, noting your location on the sheet, and place the cookie sheet into the oven, baking for 10-12 minutes,
6.
Note the exact time that the cookies go into the oven in the data table.
7.
If at any time during the baking process, you notice a strong smell of cookies, note the time in the data table.
8.
While the cookies bake in the oven, watch “The Chemistry of Cookies”, by Stephanie
Warren.
9.
While watching the video, make a list of physical and chemical changes to look for during and after the baking process.
10.
When the cookies are ready, they will be removed from the oven (BE CAREFUL, they will be HOT!!!!)
11.
Note your new, post-baking observations about the cookie [mass, volume, density, approximate temperature (cold, warm, hot), color, shape, texture, smell, and anything else you notice about the unbaked cookie]. Note these changes in the data table.
COOKIE LAB ANALYSIS QUESTIONS:
1.
What are signs that CHEMICAL CHANGES have happened?
2.
Give two examples of CHEMICAL changes that have occurred during the baking of the cookie and explain what happened.
3.
What is the difference between chemical and physical changes?
4.
Give two examples of PHYSICAL CHANGES that happen in the cookie when it is baked.

Time into oven:
Pre-Baked Mass: Pre-Baked Volume:
Time Cookie first smelled:
Post-Baked Mass:
Prebaked Density: Post Baked Density
Pre-Baked Observations (Temperature, color, shape, texture, smell, etc.)
Post Baked Volume:
PHYSICAL and CHEMICAL changes to look for during the baking process (from video)
PHYSICAL Changes CHEMICAL Changes
Post-Baking Observations (mass, approximate temperature, color, shape, texture, smell, etc.)
Time into oven:
Pre-Baked Mass: Pre-Baked Volume:
Time Cookie first smelled:
Post-Baked Mass:
Prebaked Density: Post Baked Density
Pre-Baked Observations (Temperature, color, shape, texture, smell, etc.)
Post Baked Volume:
PHYSICAL and CHEMICAL changes to look for during the baking process (from video)
PHYSICAL Changes CHEMICAL Changes
Post-Baking Observations (mass, approximate temperature, color, shape, texture, smell, etc.)