Name:
Date:
Chemistry Cookie Lab
Moles are a standard unit of measurement
in chemistry. This unit takes into account the
different elements in a chemical compound.
However, balances of compounds are often given in
grams. You can learn how to convert grams into
moles to solve chemical equations. In this lab you
will use your knowledge of molar mass to convert
from moles to grams and then use a recipe to bake
some cookies! You will need the following tables in
order to convert your recipe:
Molecular Formula Table
Use the following molecular formulas to calculate grams of ingredients. NOTE: Most of these substances
have extremely complex molecular formulas. I have greatly simplified your project by listing a
representative formula only.
Ingredient
Molecular Formula
Baking Soda
NaHCO3
Baking Powder
NaHCO3
Brown Sugar
C12H22O11
Butter
C9H14O6
White (Cane) Sugar
C12H22O11
Chocolate
C4H8O4
Cinnamon
C9H8O
Cream of Tartar
KHC4H5O6
Flour
C4H8O4
Salt
NaCl
Vanilla
C8H8O3
Eggs
C6H12O3N2
Calculations:
Do all of you conversion calculations in the space provided. Show all of your work using dimensional
analysis.
Ingredient
Molar Mass of Ingredient
Conversions
(Moles to Grams)
Gram
Measurement
Select and use a recipe below, convert moles to grams for each ingredient showing work for all of your
calculations. Record the measurements in the table:
Chocolate Chip Cookies Recipe
0.3325 mol flour
0.004188 mol baking soda
0.0045 mol salt
0.1355 mol butter (at RT)
0.55 mol sugar
Snickerdoodle Cookies Recipe
0.3875 mol brown sugar
0.078 mol eggs
0.00775 mol vanilla
0.3525 mol choc chips
0.4063 mol flour
0.004188 mol baking soda
0.002225 mol salt
0.1465 mol butter (at RT)
0.1089 mol sugar
0.0019 mol crm of tartar
0.078 mol eggs
Cinnamon Sugar:
0.008625 mol cinnamon
0.01813 mol sugar
Lab Materials:
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2 Large beakers
Beaker tongs
Foil sheet (folded into a bowl)
Foil sheet (to use as a cover for your bowl)
Gram scale or balance
Stir rod
Ingredients (you can obtain these later in the lab)
Procedure:
1. Put on safety goggles and gather your materials
2. Preheat your hot plate to a medium low setting and prewash all lab supplies
3. Calculate the total weight of all of your ingredients using your conversions sheet and record in
the data table.
4. In a beaker, melt butter and allow it to cool for 1-2 minutes. Combine butter and sugar, vanilla
(if choc chip cookies) then beat in eggs, one at a time. In a separate beaker, mix dry together
and then add dry ingredients into butter mixture. Add chocolate chips (if necessary. For the
snickerdoodle recipe, roll a spoonful of dough into balls and roll into cinnamon-sugar.
5. Place balls of dough onto the foil boil. Place foil on hot plate for a few minutes keep covered,
checking occasionally to make sure it doesn’t burn. Remove from heat and keep it covered.
Allow the cookie to continue cooking until it is lightly browned.
6. Measure the total weight of all baked cookies and record in the data table.
7. Enjoy your cookies as you complete your conclusion:
Lab Data:
Total weight of ingredients
Total weight of all baked cookies
Conclusion:
1. You baked cookies should weigh less than the ingredients total. Why does it seem like your
cookies do not follow the conservation of mass?
2. Give one example of a physical change that occurred during the lab.
3. Give one example of a chemical change that occurred during the lab.