Source: https://guthlabs.ai/docs/instruments/molar-mass-formula-mass-calculator/implementation/

instrument implementation / implementation-contract

# Molar Mass / Formula Mass Calculator implementation

A source-bound implementation contract for Molar Mass / Formula Mass Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_WITH_ERRATA**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-with-binding-errata

**Evidence ID**: t6-006

**Effect**: Computation or source lookup only

## Input and validation requirements

The extreme-count vector exposes a precision-loss break if the parser accepts subscripts above JavaScript's safe-integer limit instead of rejecting them. The convention probe also exposes a severe interpretation hazard if element-symbol capitalization is not enforced.

## Required corrections

````
[
  {
    "vector": 3,
    "field": "molar_mass_g_per_mol",
    "wrong": 342.134077,
    "correct": 342.131077,
    "cause": "transcription: own working sums 53.963077+96.180+191.988=342.131077 then field ships ...134..."
  }
]
````

## Inspectable interface fixture

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

````
{
  "inputs": {
    "formula": "H2O",
    "atomic_weights": {
      "H": 1.008,
      "O": 15.999
    }
  },
  "expected_outputs": {
    "molar_mass_g_per_mol": 18.015,
    "element_mass_breakdown_g_per_mol": {
      "H": 2.016,
      "O": 15.999
    }
  },
  "working": "Parse counts: H₂O gives n(H)=2 and n(O)=1. H contribution = 2 × 1.008 = 2.016 g/mol. O contribution = 1 × 15.999 = 15.999 g/mol. Total = 2.016 + 15.999 = 18.015 g/mol."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/molar-mass-formula-mass-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/molar-mass-formula-mass-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/molar-mass-formula-mass-calculator/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-tranche6/tranche6-results.json`

- `tranche errata record`