A factory producing Ammonia, NH₃ plan to increase the manufacturing of the yield product. The management plan to prepare a bigger size of container to collect the ammonia from the chemical reaction. Do you agree with that suggestion? Defend your answer. N₂(g) + 3H₂(g) ⇌ 2NH₃(g) ∆H = -ve CLEVER : CHALLENGE 4 LE CHATELIER’S PRINCIPLE Disagreed. The bigger the size of the container, lower the pressure inside it. The system will reduce the disturbance by increasing the pressure of the system. Equilibrium position shift to the left in order to increase the pressure to reattain the equilibrium. This will not produce more product, but will reduced it. CLEVER : CHALLENGE 4 5 MARKS HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium 49
Can you justify the effectiveness of the photochromic lens by applying Le chatelier principle and the reversible equation given. + heat CLEVER : CHALLENGE 5 LE CHATELIER’S PRINCIPLE + heat On sunny day, Temperature increase The system reduce the temperature by absorb heat. It favours endothermic reaction The equilibrium position shift to the right to reattain the equilibrium So, the lens change color to darker color on the sunny day CLEVER : CHALLENGE 5 5 MARKS HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium 50
BRILLIANT : CHALLENGE 1 Hemoglobin is important as oxygen transportation in our body. Hemoglobin will combine with oxygen in the blood and an equilibrium will be established from the attachment and dissociation of oxygen and hemoglobin. The process occurs in a reversible reaction. Hb (aq) + 4O ₂ (g) ⇋ Hb(O₂) ₄ (aq) By using this knowledge and le chatelier’s principle, can you suggest a way to prevent hiking people at the high-level mountain from shortening of breath? Clue: High level, lower pressure Hemoglobin LE CHATELIER’S PRINCIPLE By supplying the oxygen in the oxygen tank and providing the hiking people with oxygen when they feel shortening of breath. At lower pressure, the system will increase the pressure. The equilibrium position shift to the left leads to the dissociation of hemoglobin and oxygen. An oxygen tank is needed to increase the concentration of oxygen gas in the blood. It is to make sure that the combination of hemoglobin and oxygen gas can occur (forward reaction) The equilibrium position shift to the right to reattain the equilibrium . BRILLIANT : CHALLENGE 1 5 MARKS HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium 51
BRILLIANT : CHALLENGE 2 Mr. Ramlan has a factory producing Ammonia, NH₃. He is thinking of optimizing the production of NH₃ in his factory. Help Mr. Ramlan by providing FIVE designs of optimal production in his factory by applying Le chatelier’s principle. N₂(g) + 3H₂(g) ⇌ 2NH₃(g) ∆H = -ve LE CHATELIER’S PRINCIPLE N₂(g) + 3H₂(g) ⇌ 2NH₃(g) ∆H = -ve To optimize the production of product: provide medium size of tank use moderate temperature with catalyst. Increase the concentration of N₂ Increase the concentration of 3H₂ Increase pressure BRILLIANT : CHALLENGE 2 5 MARKS HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium 52
BRILLIANT : CHALLENGE 3 (Darken colour) Photochromism is a chemical process in which photochromic compound undergoes a reversible reaction with a different color. With the knowledge of Le chatelier’s principle, suggest with reason on what kind of material you need to use to create a glass with protection against harmful UV light? ∆H = Photochromic compound LE CHATELIER’S PRINCIPLE Answer: By producing glass lenses with photochromic compounds. On a sunny day, increase the temperature make the system reduce the temperature by absorbing heat. It favours endothermic reaction the equilibrium position shift to the right to reattain equilibrium The lens change color to darker colour that will help to protect the eye from UV. BRILLIANT : CHALLENGE 3 5 MARKS HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium 53
BRILLIANT : QUESTION 4 Sulphur dioxide (SO₂) is a toxic gas responsible for the odor of burnt matches. Consider the following equilibrium: 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) ∆H < 0 If Helium gas is the only substance that you have, create a condition that can change the equilibrium position so that fewer SO₂ is consumed in the reaction. LE CHATELIER’S PRINCIPLE 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) ∆H < 0 To make sure fewer SO₂ is consumed, the equilibrium position must shift to the left. This can be done by adding helium at constant pressure. Adding inert gas at constant pressure will decrease the partial pressure of gas in the system. So equilibrium position will shift to the side to produce more moles of gas to increase the pressure in order to achieve equilibrium. In this case, equilibrium position will shift to the left and fewer SO₂ will be consumed. BRILLIANT : CHALLENGE 4 5 MARKS HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium 54
BRILLIANT : CHALLENGE 5 Dinitrogen tetroxide, N₂O₄, dissociates into two NO₂ molecules in an endothermic reaction as shown in the reversible equation below. NO₂ is usually considered a primary pollutant gas because the gas is highly toxic and has long-term effects on human health. N₂O₄(g) ⇌ 2NO₂(g) ∆H=+ve By adjusting the Temperature, suggest how you can reduce the formation of NO₂ gas according to Le Chatelier principle? t₁ LE CHATELIER’S PRINCIPLE N₂O₄(g) ⇌ 2NO₂(g) ∆H=+ve To reduce the formation of NO₂ by adjusting the temperature; The Temperature should be lowered. When the Temperature is low, the system will increase the temperature by released heat. The system favors exothermic reaction. Thus equilibrium position shift to the left. NO₂ gas formation will be reduced. BRILLIANT : CHALLENGE 5 5 MARKS HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium 55
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HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium CHEMEQUI COMMUNITY Chemequi Community 63 Let’s communicate and sharing more with our students “You are like a chemical reaction, mixing knowledge, passion, and guidance to create brilliant minds. ” Thanks for being an amazing Chemistry
HOTS-CHEM_EQUI HOTS Challenge in Chemical Equilibrium REFERENCES Jusniar, J., Effendy, E., Budiasih, E., & Sutrisno, S. (2020). Misconceptions in rate of reaction and their impact on misconceptions in chemical equilibrium. European Journal of Educational Research, 9(4). https://doi.org/10.12973/eu-jer.9.4.1405 Kraska, T. (2022). Simulation Game Illustrating the Density-Le Châtelier Effect on a Chemical Equilibrium of the Type A ⇌ 2B. Journal of Chemical Education. https://doi.org/10.1021/acs.jchemed.2c00203 Mai, Y., Qian, Y., Li, L., & Lan, H. (2021). The conceptual structure of chemical equilibrium in upper-secondary school students: Evidence from factor analysis. Journal of Baltic Science Education, 20(1). https://doi.org/10.33225/jbse/21.20.80 Matriculation Division KPM (2022). Curriculum Specification Chemistry 1 SK015. Oztay, E. S., Ekiz-Kiran, B., & Boz, Y. (2023). Revealing the development of interaction among components of pedagogical content knowledge in teaching chemical equilibrium. Chemistry Education Research and Practice. https://doi.org/10.1039/d2rp00159d Plass, J. L., Homer, B. D., & Kinzer, C. K. (2015). Foundations of gamebased learning. Educational Psychologist, 50(4), 258–283. https://doi.org/10.1080/00461520.2015.1122533 Plass, J. L., Homer, B. D., Mayer, R. E., & Kinzer, C. K. (2020). Theoretical foundations of game-based and playful learning. Schrader, C. (2022). Serious Games and Game-Based Learning. In Handbook of Open, Distance and Digital Education (pp. 1-14). Singapore: Springer Singapore. Siagian, A. F., Ibrahim, M., & Supardi, Z. A. I. (2023). Creativescientific decision-making skills learning model for training creative thinking skills and student decision making skills. Nurture, 17(1). https://doi.org/10.55951/nurture.v17i1.141 64