HS-PS1-6 Equilibrium

Students who demonstrate understanding can refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.

*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.

Summary

Students who demonstrate understanding can refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.

Clarification

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.

Synonyms
HSPS1-6
PS1-6
Equilibrium
// Sunday, November 16, 2025 Tom Kuntzleman
The conversion of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) is an extremely important energy source for living organisms. Under common physiological conditions, it can be expressed as:
// Thursday, June 1, 2023 Tom Kuntzleman
An experiment that has always fascinated me is observing what happens when CO2 is bubbled into limewater (which is a saturated solution of calcium hydroxide).1-2 This experiment can be carried out by blowing bubbles of exhaled breath (which contains roughly 4% CO2)3 through a straw into limewater.
// Friday, March 4, 2022 Michael Jansen
We typically teach students to solve qualitative chemical equilibrium problems using an ICE table, where I, C, and E represent [Initial], [Change], and [Equilibrium] concentrations of each reactant and product in units of mol∙L–1. At the risk of insulting you, I’ll provide an example, liberated from our class textbook:1
What is the pressure in a soda?
// Tuesday, December 8, 2020 Tom Kuntzleman
Bottles of soda are sealed under high pressures of CO2, or PCO2. This causes a substantial amount of CO2 to dissolve into the beverage, giving the drink its fizziness. But what exactly is the pressure inside a bottle of soda?
Coke and Mentos Color Changes
// Wednesday, September 2, 2020 Tom Kuntzleman
If you know me, you know that I love the Diet Coke and Mentos reaction. It’s so simple to carry out, but yields incredible results! Just drop a few Mentos candies into a bottle of a carbonated beverage and watch the magic take place! See video 1.
Bubble Busting Water Chemistry
// Wednesday, April 29, 2020 Tom Kuntzleman
In Chemical Mystery #17, shavings of Dial soap are added to samples of Aquafina and Evian drinking water. Upon blowing into each mixture with a straw, only the Aquafina water produced stable bubbles. Why is this the case?
3 wells with solutions (red, olive green, light green) text: Colorful Copper Equilibrium
// Thursday, March 5, 2020 Tom Kuntzleman
I’d like to describe a very colorful system you can use to explore many facets of chemical equilibrium.