Download Mole POGIL

The Mole
How can we use a unit of measurement to convert between units of that substance?
Why?
What is a ​mole​? Well, it’s just a way to count specific amounts of stuff. Specifically, ​6.02 x 10​23​ (602 sextillion)
number of things. Recall that anything can be counted in moles the same way anything can be counted in dozens,
cases, or any other unit someone could imagine. In this activity, you and your lab group will be creating your own
unit of counting. Just as people invented dozens or moles, you are going to invent a new unit called the PCU. How is
a PCU like a mole?
Recall:
Why do we use such a large number for counting atoms instead of a much smaller and easier to use
number?
Model 1 - Creating the Popcorn Unit
1. Weigh out 25.0 grams of popcorn kernels on the balance and count the number of kernels there are in 25.0
grams. This number will be called 1 PCU (1 popcorn counting unit). How many kernels are in 25.0g?
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2. Complete the ​conversion factor​ for PCUS:
3. How many ​grams ​of popcorn kernels are in 1 ​PCU?
_____________ ​g/PCU
4. Write a ​for every​ statement for the number of ​grams​ of popcorn in a ​PCU:
5. How could you calculate the number of kernels in 3 PCUs:
6. How could you calculate the number of kernels in 50.0 grams of popcorn:
7. How could you calculate the mass, in grams, of 1,000 popcorn kernels:
© Stephen Watzman 2020
Model 2 - Converting PCUs
Complete the following data table: Use scientific notation when the number is 10​4​ and above
Number of Popcorn
Kernels
Number of PCUs
Mass of Popcorn Kernels (g)
2
10
500
10.0
650.0
1130g (a bag of kernels)
1
498
7,000
5.0 x 10​8
7. The highlighted row shows the data for the mass of a bag of popcorn kernels. How many kernels are in the
average bag of popcorn kernels?
8. Based on the class data table, what is the average number of kernels in the popcorn bag? Show your work.
9. How close to the class average number is the number you found?
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10. What factors could affect the number of kernels calculated by each student?
11. We can use a PCU just like a dozen is used. When we count out a dozen eggs, bagels, and marbles, we
know that the mass of each dozen will not be the same. Would you expect 1 PCU of lima beans to weigh the
same as 1 PCU of popcorn kernels? Explain.
Model 3 - Moles and PCUs
12. According to model 3, what is the mass of:
a. A mole of Copper
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b. A PCU of popcorn kernels
13. How is an atom in a mole similar to a kernel in a PCU?
14. Why would PCUs not be an appropriate unit of measurement for atoms?
15. Why would a mole not be an appropriate unit of measurement for popcorn kernels?
16. Complete the following table for Copper’s conversion units:
17. How is a mole similar to and different from a PCU?
© Stephen Watzman 2020