Source: https://guthlabs.ai/docs/instruments/molarity-solution-prep-calculator/implementation/

instrument implementation / implementation-contract

# Molarity / Solution Prep Calculator implementation

A source-bound implementation contract for Molarity / Solution Prep Calculator; 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**: t4-086

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification permits a zero-concentration stock input that produces an undefined stock-volume division, and its mixed L/mL and %w/v workflows can produce a factor-of-1000 or formula-mode error unless units and concentration mode are explicitly enforced.

## 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": {
    "target_molarity_M": 0.15,
    "final_volume_L": 0.5,
    "molecular_weight_g_per_mol": 58.44
  },
  "expected_outputs": {
    "mass_g": 4.383
  },
  "working": "Moles = 0.15 mol/L × 0.500 L = 0.0750 mol. Mass = 0.0750 mol × 58.44 g/mol = 4.383 g."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/molarity-solution-prep-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/molarity-solution-prep-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/molarity-solution-prep-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-tranche4/tranche4-results.json`