QR Challenge: Gas Stoichiometry

Created using the ClassTools QR Treasure Hunt Generator

Teacher Notes

A. Prior to the lesson:

1. Arrange students into groups. Each group needs at least ONE person who has a mobile device.

2. If their phone camera doesn't automatically detect and decode QR codes, ask students to

• Download a QR reader (e.g. I-Nigma | NeoReader | Kaywa) onto their mobile devices
• Bring these devices into the lesson.

3. Print out the QR codes.

4. Cut them out and place them around your class / school.

---

B. The lesson:

1. Give each group a clipboard and a piece of paper so they can write down the decoded questions and their answers to them.

2. Explain to the students that the codes are hidden around the school. Each team will get ONE point for each question they correctly decode and copy down onto their sheet, and a further TWO points if they can then provide the correct answer and write this down underneath the question.

3. Away they go! The winner is the first team to return with the most correct answers in the time available. This could be within a lesson, or during a lunchbreak, or even over several days!

---

C. TIPS / OTHER IDEAS

4. A detailed case study in how to set up a successful QR Scavenger Hunt using this tool can be found here.

---

Questions / Answers (teacher reference)

Question	Answer
1. Qustion1 Carbon monoxide reacts with oxygen at STP,If 1.0 L of carbon monoxide reacts with oxygen at STP, how many liters of oxygen are required to react? 2 CO + O2 ---> 2 CO2	Answer1 0.5 liter of oxygen
2. Question2 Carbon monoxide reacts with oxygen at STP, how many liters of carbon dioxide are produced? 2 CO + O2 ---> 2 CO2	Answer2 1.0 liter of carbon dioxide
3. Question3 Acetylene gas (C2H2) undergoes combustion to produce carbon dioxide and water vapor.How many liters of C2H2 are required to produce 75.0 L of CO2? 2 C2H2 + 5 O2 ---> 4 CO2 + 2 H2O	Answer3 37.5 liters of C2H2
4. Question4 Acetylene gas (C2H2) undergoes combustion to produce carbon dioxide and water vapor. If 75 liters of carbon dioxide is formed, what volume of water is produced? 2 C2H2 + 5O2 ---> 4 CO2 + 2 H2O	Answer4 37.5 liters of water.
5. Question5 Assume that 5.60 L of hydrogen gas at STP reacts with copper (II) oxide according to the following balanced equation:CuO (s) + H2 (g) ---> Cu (s) + H2O (g). How many moles of copper are produced?	Answer5 0.25 mole Copper
6. Question6 Assume that 5.60 L of hydrogen gas at STP reacts with copper (II) oxide according to the following balanced equation: CuO (s) + H2 (g)--> Cu (s) + H2O (g)	Answer6 15.88 grams of Copper
7. Question8 Assume that 8.5 L of iodine gas (I2) are produced at STP according to the following balanced equation: 2 KI (aq) + Cl2 (g) ---> 2 KCl (aq) + I2 (g). How many grams of KI were used?	Answer8 126.2 grams of KI
8. Questions9 Assume that 13.5 grams of solid aluminum react with HCl according to the following balanced equation at STP: 2 Al (s) + 6 HCl (aq)--> 2 AlCl3 (aq) + 3 H2 (g. How many moles of H2 are produced?	Answer9 0.75 mole of hydrogen
9. Question10 Assume that 13.5 grams of solid aluminum react with HCl according to the following balanced equation at STP: 2 Al (s) + 6 HCl (aq)--> 2 AlCl3 (aq) + 3 H2 (g). How many liters of H2 are produced?	Answer10 16.8 L of hydrogen
10. Question11 Calculate the volume of hydrogen gas at produced by the reaction of 0.52 grams of solid magnesium with excess hydrochloric acid, based on this chemical equation: Mg + 2HCl---> MgCl2 + H2	Answer11 0.48 L hydrogen gas
11. Question12 How many liters of hydrogen gas are needed to react completely with 50.0 L of chlorine gas at STP based on this chemical equation: H2 + Cl2 ---> 2HCl.	Answer12 50.0 L of hydrogen gas
12. Question13 Given the following reaction: 2NO (g) + O2 (g) --> 2NO2 (g) How many liters of gaseous oxygen are needed to produce 4.50 L of gaseous nitrogen dioxide, if both gases are being measured at STP?	Answer13 2.25 L of O2
13. Questions14 Given the following reaction: N2 (g) + 3H2 (g) ---> 2NH3 (g) If 200. L of ammonia (NH3)are produced in the reaction between nitrogen and hydrogen at STP, how many liters of nitrogen gas is used up in this reaction?	Answer 14 100 L nitrogen

 

---