Begin with the assigned case
Use the same names and starting values in the lesson, worksheet and lab. Show the starting case before detailed model settings.
2105603 · 2027 design preview · instructor notes
Instructor design notes
Design observations, the redesign sequence for all 13 labs and the usability-pilot protocol. Students start from the Labs 2027 overview.
What the classroom walkthrough revealed
The 13 November 2026 walkthrough surfaced four questions before the electrochemistry investigation could proceed.
- Where is the starting example?
- What do the left and right species tables represent?
- Which number changes the concentration?
- What should I try after the first calculation?
The prototype puts the starting case, editable scientific quantities and next actions together. The audit of the other labs identifies similar design risks for review.
A shared structure for the next version
Edit the quantity you understand
Label concentrations, temperature and pressure with their units. Use structured data tables and equation previews for imported measurements.
Connect a prediction to the result
Keep a short prediction near the calculate action. Show the numerical result, its physical meaning and a calculation the student can check.
Keep the comparison together
Save named cases with their inputs and notes. Reopen the study and recalculate it. Present validation messages beside the quantity that needs attention.
Redesign sequence for all 13 labs
| Lab | Preparation | Student workflow |
|---|---|---|
| 01 · VLE/flash | Graduate prototype | Establish a baseline, audit model assumptions, test phase robustness under assumed input bounds and defend the conclusion. |
| 02 · Case study | Graduate prototype | Infer activities, fit/check separate observations, quantify sensitivity to assumed measurement bounds and compare conditional fits. |
| 03 · Consistency | Graduate prototype | Check applicability, compare diagnostic methods and defend a conclusion under sampling, endpoint and measurement assumptions. |
| 04 · Stability/LLE | Graduate prototype | Connect the selected feed with Gibbs curvature, the supporting tangent and phase fractions; separate local from global evidence, test parameter sensitivity near the critical point and compare models matched at infinite dilution. |
| 05 · LLE fitting | Graduate prototype | Show the observed tie line beside the fitted common tangent; separate calibration from held-out temperatures, test fixed-α identifiability and refit within measurement bounds. |
| 06 · VLLE | Prototype · Core and Graduate | Explain the three-phase state with a vessel picture and a calculated P–x–y diagram; compare compositions across feeds, explore the family of amounts, sweep pressure across P₃ and test the heterogeneous azeotrope. |
| 07 · Adiabatic flash | Prototype · Core and Graduate | Show the valve-and-drum process and an enthalpy bookkeeping figure; solve the outlet with Q = 0, find where the flash begins, compare liquid models and compute the heater duty. |
| 08 · Experimental VLE input | Prototype · Core and Graduate | Preview how the first row is read with its units and Antoine constants, check the pure-liquid limits of ln γ, then fit; diagnose unit errors by their signatures. |
| 09 · Virial vapor | Prototype · Core and Graduate | Compare the same flash with ideal and second-virial vapors, see where φᵢ, φᵢˢᵃᵗ and Πᵢ enter K, and scale B until the truncation guard refuses the state. |
| 10 · Solid–liquid equilibrium | Prototype · Core and Graduate | Cool a binary feed with pure solids, read the tie line and the eutectic, and test the liquid model and fusion data. Sublimation (GSE) remains in the current lab. |
| 11 · Adsorption | Prototype · Core and Graduate | Share a fixed gas inventory between the free volume and a Langmuir adsorbent, read the isotherm and balance line together, and test fit range, isosteric heat and temperature swing. |
| 12 · Reaction equilibrium | Prototype · Core and Graduate | Solve A₂ ⇌ 2A from ΔG°, read the Gibbs-energy minimum, separate pressure and inert effects on Q from temperature effects on K, and test the standard-state convention. |
| 13 · Concentration cell | Prototype · Core and Graduate | Calculate E from the activity ratio, identify the cathode, relate ΔG to dilution, and test activity models, dE/dT and the work available on discharge. |
Try the prototype with a first-time student
- Open the Lab 01 starting problem, predict its phases, and calculate without verbal instructions.
- Explain the liquid and vapor compositions and check the component balance.
- Save the starting result, raise the pressure to 100 kPa, and explain the change in phase amount.
- Download the study, reopen it, and reproduce a saved comparison.
Record time, incorrect edits, places where help is needed, and the student's explanation. Include keyboard use and a narrow screen in the review.
For Lab 02, inspect the starting measurement, check your activity-coefficient calculation, fit 60 kPa, evaluate 80 kPa without refitting, and reopen a saved comparison.
For the graduate routes, ask the student to defend a claim using the sensitivity outputs, explain why the sampled range is not a confidence interval, and reopen the saved inputs and evidence record.
For Lab 03, ask the student to find the error hidden by an area criterion, explain a method marked not assessed, compare an endpoint assumption and reopen the complete diagnostic record.
For Lab 04, ask the student to classify z₁ = 0.12 before calculating, explain why positive curvature did not decide it, rerun the sensitivity at A = 2.05, and name the measurement that separates two models with the same ln γ∞.
For Lab 05, ask the student to predict what a near-zero residual shows, explain why α = 0.47 converges yet misses the tie line, and defend one τ(T) assumption using the held-out errors.
These are design prototypes for Labs 01–08 and 13. Independent student usability sessions and the remaining four lab interfaces are future work. Numerical checks use the existing course calculation engines.
Design references
Field instructions, input feedback and control sizing follow the relevant W3C guidance. Form instructions · User notifications · Target size
Graduate uncertainty discussions refer to NIST's guidance on combining uncertainty components and expanded uncertainty and coverage factors.