Six sessions · independent practice
Explain, calculate,
verify.
Allow 45–60 minutes for the required task, including its independent checkpoint. Continue from the classroom case. Retain a study JSON, one comparison and a short explanation. Optional work is additional. The independent checkpoints are deliberately small enough to calculate without the lab.
1. VLE and flash
Open core lab · Session resources and companion labs
Required investigation · 45–60 minutes total
In Lab 01, save one ideal two-phase baseline and one changed pressure at the same T and z. Predict the change, report phase amounts and check one component balance by hand.
Independent calculation
Independent checkpoint: ideal binary at fixed T, Psat1=150 kPa, Psat2=60 kPa, z1=0.5 and P=90 kPa. Calculate bubble pressure at x1=z1, dew pressure at y1=z1, x1, y1 and vapor fraction. These are specified synthetic vapor pressures, not a property correlation.
Short explanation
How does pressure change the phase split at fixed temperature? State one assumption that limits your answer.
Optional extension
Choose one extension: compare liquid activity models, examine zero versus nonzero virial coefficients in Lab 09, or add the energy balance in Lab 07.
Evidence: prediction before calculation; saved inputs with model and property sources; baseline and changed case; numerical balance or limiting-case check; supported conclusion and limitation.
2. Data, consistency and model evidence
Open core lab · Session resources and companion labs
Required investigation · 45–60 minutes total
In Lab 08, validate the supplied synthetic example and compare one-parameter Margules with NRTL at alpha=0.3 on the same observations. Report one residual pattern and verify one activity coefficient by hand.
Independent calculation
Independent checkpoint: for an ideal vapor at T=350 K, P=100 kPa, x1=0.4, y1=0.6, Psat1=150 kPa and Psat2=60 kPa, compute both activity coefficients. Explain what changes if the Psat pressure unit was mislabeled.
Short explanation
Does a small fitting error mean the data and model are trustworthy? State one assumption that limits your answer.
Optional extension
Choose one extension: a controlled consistency defect in Lab 03, a fixed held-out comparison, bootstrap fit spread, or your own sourced VLE data. Exact synthetic bootstrap spread does not quantify real measurement uncertainty.
Evidence: prediction before calculation; saved inputs with model and property sources; baseline and changed case; numerical balance or limiting-case check; supported conclusion and limitation.
3. Stability, LLE and parameter spread
Open core lab · Session resources and companion labs
Required investigation · 45–60 minutes total
In Lab 04, retain one supported tie line and compare two overall compositions inside it. Verify the lever rule by hand and explain the global stability check.
Independent calculation
Independent checkpoint: a supported tie line has xAlpha=0.1 and xBeta=0.9. For z1=0.3 compute both liquid fractions and check the balance.
Short explanation
When does a calculated liquid split represent stable equilibrium? State one assumption that limits your answer.
Optional extension
Choose one extension: NRTL tie-line fitting in Lab 05, paired bootstrap from independent replicates, or feasible three-phase amounts in Lab 06.
Evidence: prediction before calculation; saved inputs with model and property sources; baseline and changed case; numerical balance or limiting-case check; supported conclusion and limitation.
4. Solids and adsorption
Open core lab · Session resources and companion labs
Required investigation · 45–60 minutes total
In Lab 10, compare inventories above and below the solid-depletion boundary at fixed T and V. Check the inventory balance and explain the resulting gas pressure.
Independent calculation
Independent checkpoint: at T=300 K and gas volume V=1.00 L, a bulk solid has saturation pressure 10.0 kPa. With 0.0100 mol total, find gas pressure and solid remaining (ideal gas).
Short explanation
What happens to gas pressure when the solid inventory runs out? State one assumption that limits your answer.
Optional extension
Choose one extension: compare Henry and Langmuir in Lab 11, check a closed adsorption vessel, or explore pure-solid solubility and the eutectic assumptions in Lab 10.
Evidence: prediction before calculation; saved inputs with model and property sources; baseline and changed case; numerical balance or limiting-case check; supported conclusion and limitation.
5. Chemical equilibrium and routes to K
Open core lab · Session resources and companion labs
Required investigation · 45–60 minutes total
In Lab 12, compare the supplied Gibbs-energy and H−TS routes at the reference temperature. Change pressure at fixed T and compare K with equilibrium extent. Check one balance.
Independent calculation
Independent checkpoint: A(g) ⇌ B(g), deltaG°=−5.000 kJ/mol at 298.15 K, ideal gases with the same 1 bar standard. Initially 1 mol A, no B. Find ln K, K and equilibrium extent.
Short explanation
Why can composition change while the equilibrium constant stays the same? State one assumption that limits your answer.
Optional extension
Choose one extension: vary temperature with and without a heat-capacity correction, reverse the reaction, or scale its coefficients consistently.
Evidence: prediction before calculation; saved inputs with model and property sources; baseline and changed case; numerical balance or limiting-case check; supported conclusion and limitation.
6. Electrochemical equilibrium
Open core lab · Session resources and companion labs
Required investigation · 45–60 minutes total
In Lab 13, compare a concentration cell with the activities exchanged. Predict and explain the sign of E, then independently check deltaG=−nFE.
Independent calculation
Independent checkpoint: the same M2+/M reduction couple appears on both sides, T=298.15 K, aLeft=0.0100 and aRight=1.000, with equal E°. Calculate Eright−Eleft and deltaG per mole of the balanced cell reaction (n=2). Neglect junction potential.
Short explanation
What determines the sign of a concentration-cell potential? State one assumption that limits your answer.
Optional extension
Choose one extension: scale the balanced reaction and electron count, examine activity corrections within the supported model, or explain why equilibrium voltage differs from voltage under load.
Evidence: prediction before calculation; saved inputs with model and property sources; baseline and changed case; numerical balance or limiting-case check; supported conclusion and limitation.
Feedback rubric
Apply each level to each criterion separately. These descriptors support feedback; they are not registered grading weights.
| Criterion | 3 · Supported | 2 · Mostly supported | 1 · Incomplete | 0 · Missing |
|---|---|---|---|---|
| Reproducibility | Complete inputs, units, sources and restorable study | Minor metadata gap | Inputs cannot be fully reconstructed | No usable inputs |
| Thermodynamic reasoning | Correct constraints, standard states and justified model domain | Correct method with one unexamined assumption | Procedure without a defensible model choice | No relevant reasoning |
| Verification | Independent numerical check with scale and units | Relevant check with a minor omission | Only repeats solver output | No check |
| Interpretation | Explains trends, limits and distinguishes fit from evidence | Sound trend with limited discussion of uncertainty | Claims exceed the evidence | No interpretation |
Revise one weak criterion after feedback and retain both versions. For a failed calculation, a reproducible diagnosis and a justified supported alternative are meaningful evidence.