Source: https://guthlabs.ai/docs/instruments/colligative-properties-suite/implementation/

instrument implementation / implementation-contract

# Colligative Properties Suite implementation

A source-bound implementation contract for Colligative Properties Suite; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t4-183

**Effect**: Computation or source lookup only

## Input and validation requirements

- Division-by-zero and invalid-input hazards can arise in upstream calculations of molarity, molality, or mole fractions if solvent mass, solution volume, or total mole amount is zero.

- Reject negative molality, molarity, temperature, Kb, Kf, or pressure values; enforce 0≤x_solvent≤1.

- Using Celsius directly in π=iMRT produces an incorrect result; temperature must be converted to kelvin.

- Mixing molality and molarity, or using Kb/Kf with incompatible units, produces dimensionally incorrect temperature changes.

- The van't Hoff factor is not always an integer and may vary with concentration, dissociation, association, or ion pairing; treating it as exact requires an explicit approximation.

- The dilute ideal-solution formulas may be inaccurate for concentrated electrolytes or nonideal solutions.

- P°_solvent is strongly temperature-dependent; the solvent vapor-pressure table must identify the temperature and pressure units.

- The current vapor-pressure formula does not directly return the claimed vapor-pressure lowering.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "property": "boiling_point_elevation",
    "solvent": "water",
    "i": 2,
    "Kb": 0.512,
    "Kb_units": "K·kg·mol^-1",
    "m": 0.5,
    "m_units": "mol·kg^-1",
    "Tb_pure_C": 100
  },
  "expected_outputs": {
    "delta_Tb_K": 0.512,
    "new_boiling_point_C": 100.512
  },
  "working": "ΔTb=i·Kb·m=2.0×0.512×0.500=1.024×0.500=0.512 K. Tb,new=Tb°+ΔTb=100.000+0.512=100.512 °C."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/colligative-properties-suite/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/colligative-properties-suite/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/colligative-properties-suite/qualification/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`