Combustion Analysis Solver

Inspectable records

Ledger state

The current ledger marks this instrument verified with errata that must be applied at binding time.

Area

Chemistry & Materials

Tranche

tranche-2

Evidence ID

t2-027

Ledger rows

1

No ledger note is attached.

Review findings

The specification needs exact input units, molar-mass definitions, elemental-mass equations, empirical-ratio reduction rules, percentage-composition equations, and validation behavior. Vector 2 is intentionally rejected because its supplied H2O mass implies n(H)=0.300000 mol and the resulting oxygen amount is 0.015550 mol, not the C2H6O ratio; this arithmetic inconsistency must be fixed before implementation.

Formula and scope findings

• The stated mol C=mol CO2 and mol H=2·mol H2O relationships are correct only after converting CO2 and H2O masses to moles using their molar masses.
• The oxygen formula is incomplete and ambiguous: mass C and mass H must mean elemental masses calculated from mol C·12.01 and mol H·1.008, not the measured CO2 and H2O masses.
• The empirical-formula calculation is not specified: elemental mole amounts must be divided by the smallest positive mole amount and converted to an integer ratio with an explicit rounding tolerance.
• The %composition calculation is not specified; it should use inferred elemental masses divided by sample mass, multiplied by 100, or equivalent empirical-formula molar masses.
• The method is valid only when the sample contains carbon, hydrogen, and oxygen as the relevant elements and combustion is complete and quantitative.

Unit assumptions

• All sample, CO2, and H2O masses must use the same mass unit; the worked vectors use grams unless explicitly labeled milligrams.
• M(CO2)=44.01 g/mol, M(H2O)=18.016 g/mol, A(C)=12.01 g/mol, A(H)=1.008 g/mol, and A(O)=16.00 g/mol.
• CO2 and H2O masses are pure product masses after complete combustion, with no moisture, reagent, or collection-system bias.
• The sample contains no elements other than C, H, and O, and all sample carbon becomes CO2 while all sample hydrogen becomes H2O.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The solver must handle zero sample mass, zero elemental amounts, negative inferred oxygen, and the near-zero-oxygen validity transition. Without explicit validation, it can produce undefined percentages, chemically impossible formulas, or unstable empirical-formula ratios.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "sample_mass_g": 3.0026,
    "co2_mass_g": 4.401,
    "h2o_mass_g": 1.8016
  },
  "expected_outputs": {
    "empirical_formula": "CH2O",
    "percent_composition": {
      "C": 40,
      "H": 6.714,
      "O": 53.286
    }
  },
  "working": "n(CO2)=4.401/44.01=0.100000 mol, so n(C)=0.100000 mol and m(C)=0.100000×12.01=1.2010 g. n(H2O)=1.8016/18.016=0.100000 mol, so n(H)=2×0.100000=0.200000 mol and m(H)=0.200000×1.008=0.2016 g. m(O)=3.0026−1.2010−0.2016=1.6000 g, so n(O)=1.6000/16.00=0.100000 mol. Mole ratio C:H:O=0.100000:0.200000:0.100000=1:2:1, giving CH2O. Formula mass=12.01+2(1.008)+16.00=30.026 g/mol. %C=12.01/30.026×100=40.000%; %H=2.016/30.026×100=6.714%; %O=16.00/30.026×100=53.286%."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_WITH_ERRATA
• evidence-tranche2/tranche2-results.json
• BOUNDARY_HAZARD_CATALOG.json