Percent Composition and Practical Applications GUM LAB % COMPOSITION

Tuesday March 8 th 2016 – B Day  Objective: Students will be able to calculate the percent composition of sugar in various brands of chewing gum.  Homework Due: Percent Composition Practice  Agenda:  Warm-up  Go Over Homework  Gum Lab Introduction/Lab  Quiz  Homework: Gum Lab Write-up Due Thursday 3/10  Warm-up: 1. Calculate the % composition of propane C 3 H 8

How would you find the % of fat in a slice of pepperoni pizza?  Jot down some ideas on your white board  What quantities would you need to know?  Where would you look to find the quantities needed?  Write an equation to find the % of fat in a slice of pepperoni pizza  After 1 minute, I will ask you to talk to your neighbor and share your ideas with one another. Be prepared to share your answers with the class.  * Note: This is not the % of fat that you find on the nutrition label –remember that’s the % of your recommended daily value of fat intake, not the percent that is actually in the pizza!

Practice  An entire large pepperoni pizza weighs 568 grams. There are 8 slices of pizza total. Each slice contains 28 grams of fat. Calculate the % fat in one slice of pepperoni pizza.

More Practice  You just received a fruit dehydrator for your birthday and you cannot wait to try it out!  You are interested to see how much water is in an apricot. You weigh the apricot before you place it in the dehydrator and see that it weighs 27 grams.  When you remove it from the dehydrator it only weighs 3.3 grams.  Work with your partner to answer the questions below on your whiteboard 1. How much water (in grams) was in the apricot? 2. Calculate the % composition of water in the apricot.

Gum Lab Procedure/Expectations  You will be placed into groups of 3-4 and assigned a lab station  Once prompted, go to your lab station. I will come around and pass out a piece of gum to each of you. Each person will receive a different type of gum.  You MUST weigh the gum before beginning to chew it ! DO NOT EAT IT RIGHT AWAY.  Weigh the gum in the wrapper. Once you have recorded the mass of the gum in the data table you can begin chewing the gum, but make sure to SAVE THE WRAPPER  You will need to chew your gum for at least 7 minutes – someone should start a timer on their phone. While you are chewing your gum, write a hypothesis for the lab and answer the pre-lab questions. You may also weigh your gum wrapper at this time.  Once you have chewed your gum for 10 minutes, spit the gum into the wrapper and place the gum on the scale. Record the mass on the data table.

Lab Procedure/Expectations Cont…  Everyone should be participating in the lab and staying on-task.  You should remain at your assigned lab stations and be working with your group members, not wandering around the room.  There should not be any arguing about which type of gum you receive or you will not get any and will have to complete the lab using another lab group’s data.  If you have questions, please raise your hand and wait patiently for me to come to you.

Checks for Understanding  On your white board, write the answers to the following questions and show me your answers when prompted by Ms. Kristoff 1. What should you do when you get your piece of gum? Keep it in the wrapper and weight it. 2. What do you do with the gum wrapper after you begin chewing your gum? Keep it to place your chewed gum in later. 3. How long do you need to chew your gum before weighing it the second time? 7 minutes

Nutrition Information from Gum  Use the following information to complete # 5 and 6 on your lab report  Extra Polar Ice  Mass = 2.7 grams  Sugar Alcohol= 2 grams  Orbit Sweet Mint  Mass = 1.9 grams  Sugar Alcohol = 1 gram  Doublemint  Mass = 2.7grams  Sugar = 2 grams