If a student “gets the wrong answer” while performing mole conversions, it can be difficult (for both student and the teacher) to discern where an error was made. Inevitably sometime toward the beginning of learning these conversions, students can become overly confident, plugging numbers in without thinking about whether they are sensical. This card set slows students down to think about the order and purpose of each of the steps in mole conversions. The best part of the activity (in my opinion) is that each set contains an unnecessary card!

**Editor's Note:** Are you teaching virtually? This activity could easily be used virtually. See Adapting Card Sorts for Digital Instruction.

mole conversions

mole ratio

**NGSS Alignment: HS-PS1-7** Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction. [Clarification Statement: Emphasis is on assessing students’ use of mathematical thinking and not on memorization and rote application of problem-solving techniques.]

Students should be familiar with conversion factors involving the mole. Students should have had some practice trying to set up conversion factors between mass, moles, and particles so that this activity is meaningful to them.

**FOR THE TEACHER:**

1. Give the student(s) one question set (figure 1).* Be sure to log into your account to access the Student Document including all six question sets in the Supporting Information below.*

**Figure 1: **Card set for Question #1.

a. Have students find the “DIRECTIONS” card (figure 2).

**Figure 2:** Directions card

b. Bring attention to Directions 4 & 5 to save time and confusion.

3. Let work commence, and walk around to monitor.

a. Did students identify the question (figure 3)?

**Figure 3:*** Question card for card set #1*

b. Did students set up the cards correctly (figure 4)?

**Figure 4:** Correct order of cards for Question #1

c. Did students find the unnecessary card (figure 5)?

**Figure 5:** Unnecessary card for set #1

4. Have students travel around the room to the next question when they finish.

Print the 6 problem sets. Choose a different color of paper for each problem. *Be sure to log into your account to access the Student Document including all six question sets in the Supporting Information below.*

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## NGSS

Students who demonstrate understanding can use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.

*More information about all DCI for HS-PS1 can be found at https://www.nextgenscience.org/dci-arrangement/hs-ps1-matter-and-its-interactions and further resources at https://www.nextgenscience.org.

Students who demonstrate understanding can use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.

Assessment does not include complex chemical reactions.

Emphasis is on using mathematical ideas to communicate the proportional relationships between masses of atoms in the reactants and the products, and the translation of these relationships to the macroscopic scale using the mole as the conversion from the atomic to the macroscopic scale. Emphasis is on assessing students’ use of mathematical thinking and not on memorization and rote application of problem - solving techniques.