Interactive pH scale explorer
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Edit the pH Explorer MicroSim using the p5.js editor
About this MicroSim
Move a vertical cursor across a 0–14 pH scale to see color-coded pins for real substances (gastric acid, lemon juice, blood, seawater, bleach, etc.). As you slide, a live panel displays pH, pOH, \([\ce{H^+}]\), \([\ce{OH^-}]\), and an acidity/basicity description, reinforcing how logarithmic concentration changes map onto everyday chemicals.
How to use
- Drag the pH slider (0–14, step 0.1) or click the scale to move the cursor.
- Watch the [H⁺], [OH⁻], and pOH readings update automatically (\([\ce{H^+}] = 10^{-\text{pH}}\)).
- Compare the cursor color and text classification (strongly acidic, neutral, strongly basic).
- Hover over or simply read the pinned labels to contextualize where common substances fall.
Classroom ideas
- Give students a list of pH values and have them match each to a real substance on the scale.
- Ask learners to predict [H⁺] for a given pH, then verify it in the panel and note how doubling the pH reduces [H⁺] by 100×.
- Use the classification text to spark discussion about the differences between weakly and strongly acidic/basic solutions.
- Build lab prework: students locate buffer pH targets and explain why the color region matters.
Learning goals
| Item | Details |
|---|---|
| Subject area | Chemistry — acid-base theory |
| Grade band | Grades 10–12 and introductory college |
| Learning objective | Students will interpret the pH scale to identify relative acidity/basicity and convert between pH, pOH, \([\ce{H^+}]\), and \([\ce{OH^-}]\). |
| Bloom's level | Apply |
| Duration | 8–10 minutes |
| Prerequisites | Logarithmic pH definition, conjugate acid/base knowledge |
| Assessment ideas | Quick journal entry: “At pH 5, what are [H⁺], [OH⁻], pOH, and a real-world example?” |
Instructional design review
- Single objective: “Students use the pH scale to relate colors, examples, and quantitative conversions.” ✔️
- Control inventory: one slider plus the responsive info panel (no extra buttons).
- Progressive disclosure: only the selected cursor data updates; pins remain as context.
- Accessibility: large fonts, color + labels, slider accessible via keyboard.
Lesson plan
Grade level
High school chemistry (Unit on acids/bases) or introductory college
Duration
10-minute exploration or bell-ringer
Prerequisites
- Definition of pH/pOH
- Relationship between [H⁺], [OH⁻], Kw
Activities
- Warm-up (3 min): Instructor demonstrates the gradient and pins.
- Student exploration (5 min): Learners slide to three specific pH values and record all computed quantities.
- Wrap-up (2 min): Share how a unit change on the pH scale affects concentration (×10).
Assessment
- Exit ticket: “If blood is pH 7.4, what is [H⁺]? Where does household ammonia fall relative to blood?”
- Extension: Students screenshot a region (e.g., weakly basic) and annotate it with two examples.
References
- Tro, N. J. Chemistry: A Molecular Approach, 5th ed., Pearson, 2020 — pH scale fundamentals.
- Zumdahl & Zumdahl. Chemistry, 11th ed., Cengage, 2020 — pH/pOH conversions and typical household examples.