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Integrated Rate Law Grapher

Run the grapher fullscreen
Edit the MicroSim in the p5.js editor

About This MicroSim

Three stacked plots show \([A]\) vs. \(t\), \(\ln [A]\) vs. \(t\), and \(1/[A]\) vs. \(t\) for the same initial conditions. Choosing the reaction order highlights the linear plot (green tint) and displays the slope, reinforcing which integrated rate law applies. Sliders let you change \(k\), \([A]_0\), and the time window; the graph responds immediately.

How to Use

  1. Choose Reaction Order (zero, first, or second). The linear plot will turn green with a label noting the order.
  2. Adjust k, [A]₀, and Time Range sliders to see how concentration profiles change. Units update automatically.
  3. Read the slope text beneath the linear plot to obtain \(k\) from its negative (zero/first order) or positive (second order) slope.
  4. Press Reset to return to the default first-order scenario.

Classroom Ideas

  • Order Detection: Give students mystery data points, then have them match the linear plot in the MicroSim to determine reaction order.
  • Lab Companion: Use the grapher alongside a kinetics experiment to predict which plot should be linear before fitting real data.
  • Slope Practice: Ask learners to write down \(k\) from the slope readout and check it against the slider value for each order.
  • Comparative Analysis: Have groups compare how quickly concentrations drop for different orders but identical initial conditions.

Lesson Plan

Grade Level

Grades 11–12 (AP Chemistry Unit 5) and college kinetics

Duration

15-minute guided exercise or homework helper

Prerequisites

  • Understanding of zero/first/second order integrated rate laws
  • Comfort with natural logarithms and reciprocal plots
  • Ability to interpret slope as the rate constant

Activities

  1. Demo (3 min): Teacher shows how the linear plot shifts when the order dropdown changes.
  2. Hands-on (8 min): Students adjust sliders to match preset scenarios and fill in a worksheet (order, \(k\), slope relation).
  3. Wrap-up (4 min): Learners write one sentence explaining why only one plot is linear for each reaction order.

Assessment

  • Exit ticket: “In a first-order reaction with \(k = 0.30\,\text{s}^{-1}\), which plot is linear and what is its slope?”
  • Homework: Students copy the MicroSim’s slope text for all three orders and annotate the integrated rate laws they correspond to.

References

  1. Chang & Goldsby, Chemistry, 13th ed., McGraw Hill, 2019 — Integrated rate law derivations.
  2. College Board, AP Chemistry Course and Exam Description, 2023 — Topic 5.1 (reaction order and rate laws).