Team Charter — Rocket Chemistry
Mission
Run the quantitative chemistry that answers the engineering question: given our measured H₂O₂ decomposition rates and our measured fuel calorimetry, is the design oxidiser flow sufficient to support the designed ethanol burn?
You produce three calibration curves from the H₂O₂/KMnO₄ rates lab, two energy-output curves from ethanol and methane calorimetry, and a single worked-stoichiometry document that combines them into an engineering answer.
The Walter rocket (1937), the Bell Rocket Belt, and the X-1 turbopump were all driven by the same chemistry you measure in this lab.
Roles (rotate weekly)
| Role | Responsibility |
|---|---|
| Lead | Schedules team work, attends cross-team standup |
| Deputy Lead | Steps up if Lead absent; owns ICD interface checks |
| Safety Officer | Owns SOP-02 (H₂O₂ student work), observes SOP-03 (teacher 35% demo) |
| Build | Assembles separating-funnel rates rig, water-bath calorimeter |
| Recorder | Owns data tables; archives raw CSVs |
| Analyst | Fits calibration curves, runs stoichiometric calculation |
Deliverables
| ID | Deliverable | Due | Consumer |
|---|---|---|---|
| RC-D1 | Pre-lab hypothesis: how do [H₂O₂], [KMnO₄], and T affect O₂ evolution rate from catalysed H₂O₂ decomposition? | W2L4 | All teams + Lab Report 1 |
| RC-D2a | Calibration curve 1: O₂ rate vs [H₂O₂] (3% and 6%) at fixed [KMnO₄] and T | W2L5 | Comp Eng, Lab Report 1 |
| RC-D2b | Calibration curve 2: O₂ rate vs [KMnO₄] at fixed [H₂O₂] and T | W2L5 | Comp Eng (catalyst saturation analysis), Lab Report 1 |
| RC-D2c | Calibration curve 3: O₂ rate vs T (Arrhenius) at fixed [H₂O₂] and [KMnO₄] | W2L5 | Comp Eng (activation energy), Lab Report 1 |
| RC-D3 | 35% extrapolation prediction: from RC-D2a/b/c, predict the O₂ rate at 35% H₂O₂ before the teacher demo | W2L5 (before demo) | Lab Report 1 |
| RC-D4 | 35% measured rate (teacher demonstration; team records the measurement) | W2L5 | RC-D5 |
| RC-D5 | Reconciliation: predicted (RC-D3) vs measured (RC-D4); named mechanism for any residual | W2L5 | Lab Report 1 |
| RC-D6 | Ethanol calorimetry: chemical power output (W) vs fuel flow rate; comparison to ethanol LHV (26.8 MJ/kg) | W3L9 | Comp Eng (efficiency factor), Lab Report 2 |
| RC-D7 | Methane calorimetry: same approach, for comparison | W3L9 | Comp Eng, Lab Report 2 |
| RC-D8 | Stoichiometric worked answer: given measured H₂O₂ rate and measured ethanol calorimetry, can 35% H₂O₂ at school-flow supply enough O₂ for a 0.5 g/min ethanol burn? Show working. | W3L12 | Manufacturing (informs vendor RFQ), Lab Report 3 |
| RC-D9 | Standalone titration write-up: HCl + NaOH endpoint with phenolphthalein | W2L4 | Lab Report 1 (neutralisation coverage) |
| RC-D10 | Mg + HCl pop test demonstration (10 min, qualitative H₂ identification) | W1L3 | Lab Report 1 |
| RC-D11 | Final propellant brief: stoichiometric ratios, energy density, recommendation for vendor RFQ | W3L11 | Manufacturing (vendor RFQ) |
Syllabus dot points owned
NSW Stage 5 Science:
- CW1 chemical change at the particle level
- CW2 types of reactions:
- Decomposition (H₂O₂ → H₂O + O₂; catalysed)
- Synthesis (combustion) (ethanol/methane + O₂ → CO₂ + H₂O)
- Single displacement (Mg + HCl → MgCl₂ + H₂; demonstration scale)
- Neutralisation (HCl + NaOH)
- CW3 rates of reaction — primary coverage via the H₂O₂/KMnO₄ three-variable calibration
- CW4 activation energy and catalysts — Arrhenius fit from RC-D2c
- WS5.1 Questioning and predicting (RC-D1, RC-D3)
- WS6 Conducting investigations (the rates lab + calorimetry)
- WS7.2, 7.3 Processing and analysing data (calibration-curve fitting; residual analysis in RC-D5)
- WS8 Problem solving (the stoichiometric worked answer in RC-D8)
Weekly milestones
| Week | Milestone | Evidence |
|---|---|---|
| W1 | Hypothesis written; SDS reviewed for H₂O₂ 35% (student awareness); Mg+HCl pop test done | RC-D1 + signed SDS log + RC-D10 |
| W2 | All three H₂O₂ calibration curves measured; 35% prediction issued; teacher 35% demo observed; reconciliation written; standalone titration completed | RC-D2a/b/c, RC-D3, RC-D4, RC-D5, RC-D9 |
| W3 | Ethanol + methane calorimetry done; stoichiometric worked answer written; propellant brief delivered | RC-D6, RC-D7, RC-D8, RC-D11 |
| W4 | Reconciliation against vendor telemetry (if delivered); final report contribution | Final report |
Team-specific risks (this team’s lab work)
- R-16 Mg + HCl H₂ evolution — ventilated reaction flask, max 0.5 g Mg per run, no ignition source within 0.5 m (other than the deliberate pop test ignition with the Bunsen splint)
- R-17 1 M HCl / NaOH skin contact — nitrile gloves, eyewash
- R-04, R-05 present only during LPG flame demo (run by Test Director, this team records calorimetry)
- R-18 NEW 3% and 6% H₂O₂ skin contact — nitrile gloves, goggles (low concentration, standard Stage 5)
- Teacher demonstration only: 35% H₂O₂ + KMnO₄ — team observes from 2 m line; teacher controls reagent dispensing (see SOP-03)
The H₂O₂ calibration lab design
You run three separate experiments with one variable changing each time. Use a separating-funnel-into-flask rig with an inverted graduated cylinder over a water trough for gas collection. Record gas volume every 10 s for 60-180 s. Fit a linear initial-rate slope.
Experiment 1 — Rate vs [H₂O₂]
| Variable | Values |
|---|---|
| [H₂O₂] (independent) | 3% (drugstore), 6% (drugstore-strong) |
| [KMnO₄] (controlled) | 0.10 M |
| Temperature (controlled) | 25 °C ± 1 |
| Volume H₂O₂ aliquot | 50 mL |
| KMnO₄ delivery | drip via separating funnel, 1 drop/s |
Fit a line through (0, 0) to your two points; extrapolate to 35%. This is the prediction in RC-D3.
Experiment 2 — Rate vs [KMnO₄]
| Variable | Values |
|---|---|
| [KMnO₄] (independent) | 0.05, 0.10, 0.20, 0.40 M |
| [H₂O₂] (controlled) | 6% |
| Temperature (controlled) | 25 °C ± 1 |
Look for catalyst saturation — does the curve plateau? At what [KMnO₄] does adding more catalyst stop helping? Real implication: the vendor’s peroxide system needs enough catalyst to be in the saturated regime, because their O₂ flow demand is set by the engine, not by the catalyst.
Experiment 3 — Rate vs T (Arrhenius)
| Variable | Values |
|---|---|
| Temperature (independent) | 15 °C, 25 °C (room), 35 °C, 45 °C (warmed water bath) |
| [H₂O₂] (controlled) | 6% |
| [KMnO₄] (controlled) | 0.10 M |
Plot ln(rate) vs 1/T; slope is −Eₐ/R. Compute the apparent activation energy. Compare to literature value for KMnO₄-catalysed H₂O₂ decomposition (~56 kJ/mol). Real implication: the vendor’s chamber warms during the burn, and the peroxide decomposition catalyst bed needs to operate stably across that temperature swing — your Arrhenius fit tells the vendor how much rate changes per 10 °C.
Calorimetry lab design — ethanol and methane
Standard water-bath calorimetry with a thermocouple:
- Pre-weighed ethanol burner (or LPG cylinder for methane).
- Bunsen-style flame heating ~200 mL of water in an aluminium beaker.
- K-type TC reads water temperature every 5 s.
- Run for 60 s; compute heat absorbed (Q = m·c·ΔT).
- Reweigh ethanol burner to get fuel mass consumed.
- Compute chemical power: P = Q/Δt.
- Compare to literature LHV (ethanol 26.8 MJ/kg; methane 50.0 MJ/kg).
- Combustion efficiency = (measured P / theoretical P from LHV × ṁ).
Repeat at two fuel flow rates per fuel. Plot P vs ṁ_fuel.
The stoichiometric worked answer (RC-D8) — what’s in it
Given:
- Your measured [H₂O₂] vs rate curve (from RC-D2a, extrapolated to 35%)
- Your measured ethanol calorimetry (from RC-D6)
- The vendor’s design ethanol flow rate (0.5 g/min, set by Manufacturing)
Compute:
- O₂ demand for the ethanol burn: (ethanol mass flow) × (3 mol O₂/mol ethanol × 32 g/mol ÷ 46 g/mol) = O₂ mass flow
- Convert to O₂ volumetric flow at STP
- Required H₂O₂ flow rate (35%) to produce that O₂ rate
- Compare to your measured rate; is the school-scale rig sufficient?
If yes, conclude: “In principle, 35% H₂O₂ at flow X mL/min could supply the oxidiser for a 0.5 g/min ethanol burn at our design point. The vendor’s actual implementation uses [O₂ from cylinder | LOX | H₂O₂], which is their engineering choice.”
If no, conclude: “35% H₂O₂ at any reasonable school-scale flow cannot supply the oxidiser. The vendor must use a stronger oxidiser source. This is consistent with the Walter rocket history — they used 80% H₂O₂.”
Either conclusion is a valid Year 10 engineering result.
What you don’t do
- You don’t electroplate (out of scope)
- You don’t fabricate the chamber (Manufacturing)
- You don’t handle the pressurised burn (vendor)
- You don’t measure chamber wall temperature (Heat Exchanger)
- You don’t dispense 35% H₂O₂ (teacher only)
Cross-team interfaces
- From Materials: Cu coupons for galvanic series demonstration
- From Manufacturing: design ethanol flow rate for the stoichiometric calc
- To Manufacturing: RC-D11 propellant brief
- To Comp Eng: measured calibration curves + calorimetry (for Rust crate parameters)
- To Heat Exchanger: burn-duration estimate from calorimetry
- To everyone: RC-D8 — the worked engineering answer about feasibility
Lab report assignments
Every team member writes Lab Report 1 (rates calibration + standalone titration + Mg pop test + reconciliation) individually using shared data. Lab Reports 2-4 are written by all students across all teams using program-wide data.