Gas Stoichiometry / Molar Volume Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Chemistry & Materials

Tranche

tranche-4

Evidence ID

t4-147

Ledger rows

1

No ledger note is attached.

Review findings

The core equations are standard, but the specification needs explicit STP convention, reaction balancing and limiting-reactant rules, separate input and target conditions when applicable, unit validation, and a fixed atomic-weight table. The third vector exposes an unresolved atomic-weight inconsistency: the listed sulfur value is 32.06, whereas common tables may use 32.065 or 32.06, changing the expected SO3 mass.

Formula and scope findings

• The formulas are standard and correct only when the reaction is balanced and the stoichiometric coefficients are applied to the converted mole quantities.
• The STP constant 22.414 L/mol assumes 273.15 K and 1 atm; STP is convention-dependent, and 1 bar STP would instead be approximately 22.711 L/mol.
• PV=nRT requires absolute temperature in kelvin and mutually consistent pressure-volume units.
• For reactions with multiple reactants, the specification must define limiting-reactant handling; using only one supplied species can overpredict the target amount when another reactant is limiting.
• The specification does not state whether given and target gases may have different conditions; those conditions must be represented separately if so.

Unit assumptions

• STP test cases use T=273.15 K and P=1 atm, with 22.414 L/mol.
• Non-STP pressure and volume units must match the selected gas constant: R=0.082057 L·atm·mol^-1·K^-1 for L and atm, or R=0.083144626 L·bar·mol^-1·K^-1 for L and bar.
• Masses are in grams, volumes are in liters unless explicitly converted, and temperatures are absolute kelvin.
• Atomic weights used here are N=14.007, H=1.008, Ca=40.078, C=12.011, O=15.999, S=32.06, and Cl=35.45 g/mol.
• Gases are treated as ideal, and the specified gas phase is used for target volume calculations.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

A zero-pressure input produces an undefined division in the PV=nRT branch and requires rejection. A negative mass also exposes an unresolved sign convention: signed arithmetic gives -44.828 L, while a physical-amount interpretation gives +44.828 L or should reject the input.

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": {
    "reaction": "N2 + 3 H2 -> 2 NH3",
    "given_species": "H2",
    "given_amount": "3.000 mol",
    "target_species": "NH3",
    "conditions": "STP: 273.15 K, 1 atm"
  },
  "expected_outputs": {
    "target_moles_NH3": 2,
    "target_volume_L_NH3": 44.828,
    "target_mass_g_NH3": 34.062
  },
  "working": "1. Stoichiometric ratio: n(NH3)/n(H2)=2/3. 2. n(NH3)=3.000 mol H2 × (2 mol NH3/3 mol H2)=2.000 mol NH3. 3. V(NH3)=2.000 mol × 22.414 L/mol=44.828 L. 4. M(NH3)=14.007 + 3×1.008=17.031 g/mol. 5. m(NH3)=2.000 mol × 17.031 g/mol=34.062 g."
}

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_CLEAN
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json