The performance expectation selected for this lesson (and one of the unit PEs) is:
The phenomena selected is an introductory lab where students investigate and observe three equilibrium reactions.
The learning performances students will complete during this lesson, based on the phenomena are:
For performance expectation HS-PS1-6, the clarification statement says, “Emphasis is on the application of Le Chatelier’s Principle and on refining designs of chemical reaction systems, including descriptions of the connection between changes made at the macroscopic level and what happens at the molecular level. Examples of designs could include different ways to increase product formation including adding reactants or removing products.”
The relevant section of the Framework is, “Although a solution or a gas may have constant chemical composition—that is, be in a steady state—chemical reactions may be occurring within it that are dynamically balanced with reactions in opposite directions proceeding at equal rates (p. 110).” From the grade 12 band description, students need to understand that, “In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present (p. 111).”
The content related to this phenomena is Le Chatelier’s Principle. In the phenomena lab the students make macroscopic level observations of color changes, and then begin to connect that to how stress on a reaction system affects the reaction rates and amounts of product and reactant.
SEP Content:
From the SEP matrix in the 9-12 Grade band, this section is addressed:
CCC Content:
From the CCC matrix for Stability and Change, these sections are addressed:
- HS-PS1-6: Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.
The phenomena selected is an introductory lab where students investigate and observe three equilibrium reactions.
The learning performances students will complete during this lesson, based on the phenomena are:
- LP1: Students will make observations about the effects of changing variables on reaction direction.
- LP2: Students will ask questions about the effects of changing variables on reaction direction.
- LP3: Students will develop a model to explain the effects of changing variables on reaction direction.
For performance expectation HS-PS1-6, the clarification statement says, “Emphasis is on the application of Le Chatelier’s Principle and on refining designs of chemical reaction systems, including descriptions of the connection between changes made at the macroscopic level and what happens at the molecular level. Examples of designs could include different ways to increase product formation including adding reactants or removing products.”
The relevant section of the Framework is, “Although a solution or a gas may have constant chemical composition—that is, be in a steady state—chemical reactions may be occurring within it that are dynamically balanced with reactions in opposite directions proceeding at equal rates (p. 110).” From the grade 12 band description, students need to understand that, “In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present (p. 111).”
The content related to this phenomena is Le Chatelier’s Principle. In the phenomena lab the students make macroscopic level observations of color changes, and then begin to connect that to how stress on a reaction system affects the reaction rates and amounts of product and reactant.
SEP Content:
From the SEP matrix in the 9-12 Grade band, this section is addressed:
- Ask questions to determine relationships, including quantitative relationships, between independent and dependent variables (p. 1)
- Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system (p. 2).
CCC Content:
From the CCC matrix for Stability and Change, these sections are addressed:
- “For both designed and natural systems, conditions that affect stability and factors that control rates of change are critical elements to consider and understand (p. 2).”
- “Feedback (negative or positive) can stabilize or destabilize a system (9-12th grade band, p. 2).”
- “Events have causes, sometimes simple, sometimes multifaceted. Deciphering causal relationships, and the mechanisms by which they are mediated, is a major activity of science and engineering (p. 1).”
- “Changes in systems may have various causes that may not have equal effects (9-12th grade band, p. 1)
