HS-PS1-6

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Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.

Clarification statement: 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.

Assessment boundary: Assessment is limited to specifying the change in only one variable at a time. Assessment does not include calculating equilibrium constants and concentrations.

Note: this performance expectation integrates traditional science content with engineering through a Practice or Disciplinary Core Idea.

Assessment

What assessment of HS-PS1-6 might look like on a NY state exam.

Exam	Cluster	Question
August 2026	Pool Water Chemistry	Question 24
June 2026	Equilibria in the Blood	Question 14

Performance Level Descriptions

PLDs communicate the knowledge and skills expected of students to demonstrate proficiency in each Learning Standard. NYS assessments classify student performance into one of five levels.

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Level 1: Use information provided to identify a change in the experimental conditions that would modify the amount of products or reactants at equilibrium.

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Level 2: Identify a modification to the design or to the experimental conditions of a chemical system and/or describe the effect on the products and/or reactants at equilibrium.

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Level 3: Explain how a change in the design of a chemical system and/or experimental conditions would affect the amount of products and/or reactants at equilibrium.

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Level 4: Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.

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Level 5: Optimize the design of a chemical system by explaining how multiple changes to experimental conditions will increase the amounts of products in a system at equilibrium.

Vocabulary

Terms from the Chemistry Glossary that come from this standard or from the released exam questions that assess it.

From this standard

• chemical reaction
• chemical reaction system
• chemical system
• concentration
• criteria
• design solution
• dynamic equilibrium
• equilibrium
• equilibrium constant
• evidence
• Le Chatelier’s Principle
• macroscopic level
• molecular level
• optimize
• particle
• product
• reactant
• reaction
• reverse reaction
• system
• variable

From released exam questions

• catalyst – June 2026
• claim – Aug 2026
• equilibrium shift – Aug 2026
• forward reaction – June 2026
• gas – June 2026
• investigation – June 2026
• mole – June 2026
• pressure – June 2026
• stress (on an equilibrium system) – June 2026
• volume – June 2026

Implied by this standard

• reversible reaction – implied by "balance between a reaction and the reverse reaction"

Resources

Examples and discussion of resources for the learning, teaching, and assessment of HS-PS1-6.

This section could be expanded upon. You can help out by adding to this section.

NGSS Dimensions

Performance expectation HS-PS1-6 was developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

• Constructing Explanations and Designing Solutions
  • Refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations.

Disciplinary Core Ideas

• PS1.B: Chemical Reactions
  • (NYSED) In many situations, a dynamic and condition dependent balance between a reaction and the reverse reaction determines the numbers of all types of particles present.
• EST1.C: Optimizing the Design Solution
  • Criteria may need to be broken down into simpler ones that can be approached systematically, and decisions about the priority of certain criteria over others (tradeoffs) may be needed.

Crosscutting Concepts

• Stability and Change
  • Much of science deals with constructing explanations of how things change and how they remain stable.

Page contributors: Conrad Richman, Caroline Leonard

Chemistry | HS. Chemical Reactions