Source: https://guthlabs.ai/docs/instruments/le-chatelier-shift-predictor/

instrument / verified-clean

# Le Chatelier Shift Predictor

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

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/le-chatelier-shift-predictor/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/le-chatelier-shift-predictor/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/le-chatelier-shift-predictor/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/le-chatelier-shift-predictor/qualification/>)

## Ledger state

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

**Area**: Chemistry & Materials

**Tranche**: tranche-6

**Evidence ID**: t6-078

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The core Le Chatelier rules are chemically standard for qualitative teaching, and the honest-label warning is appropriate. Review is required because the input schema does not explicitly encode balanced stoichiometry, phases, constant-volume versus constant-pressure conditions, inert-gas behavior, or the exact meaning and units of ΔV and ΔT.

### Formula and scope findings

- The rule-based method is standard for qualitative equilibrium-shift prediction, but the reaction must be balanced, reversible, and annotated with physical phases and gas stoichiometry.

- Pressure/volume shifts require distinguishing a change in system volume from addition of an inert gas and require constant-temperature assumptions; the specification does not state these constraints.

- The meaning of input ΔV is ambiguous: it could mean a reactor-volume change or the reaction's stoichiometric volume change.

- Temperature predictions require a stated positive or negative temperature change and apply the ΔH sign only to the forward reaction as written.

- Concentration changes to pure solids or pure liquids do not generally shift equilibrium because their activities are approximately constant; this constraint is not stated.

- The method should explicitly handle no-op stresses, equal gas-mole counts, catalysts, and inert-gas additions, which do not shift equilibrium under specified conditions.

### Unit assumptions

- Concentration stresses are interpreted as molarity changes at constant temperature and volume unless otherwise specified.

- Pressure/volume stresses are interpreted for gas-phase species at constant temperature; decreasing volume means increasing pressure and increasing volume means decreasing pressure.

- Temperature changes may be supplied in K or °C differences because temperature differences have the same numerical size, but absolute temperature should be in kelvin if quantitative behavior is later added.

- ΔH is interpreted as the sign of the forward reaction as written.

- Species phases are required; pure solids and pure liquids are treated as having constant activity.

- A reaction with no stated stress magnitude is treated qualitatively: any nonzero directional change is sufficient to predict a shift.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

The input ΔH = 0 is numerically ordinary but lies outside the required positive/negative enthalpy classification. Without explicit validation, a rule engine could incorrectly choose a temperature-shift direction instead of rejecting or returning undefined.

## 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(g) + 3 H2(g) ⇌ 2 NH3(g)",
    "delta_H_sign": "negative",
    "stress": {
      "type": "concentration",
      "action": "add",
      "species": "H2",
      "amount": "positive"
    }
  },
  "expected_outputs": {
    "shift_direction": "right, toward NH3",
    "rationale": "Adding a reactant consumes the added H2; equilibrium shifts in the direction that removes H2.",
    "stoichiometric_check": "Left side contains H2; rightward reaction consumes 3 mol H2 per 2 mol NH3 formed."
  },
  "working": "1. Identify the stressed species: H2. 2. H2 is on the left side, so the forward/right reaction consumes it. 3. Therefore the predicted shift is right, producing more NH3. 4. Stoichiometric check: 1 forward extent consumes 3 H2 and forms 2 NH3; the direction is unambiguous."
}
````

## 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-tranche6/tranche6-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`