Mole Fraction / Mole Percent Calculator implementation

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

t4-015

Effect

Computation or source lookup only

Input and validation requirements

• If all component amounts are zero, Σn = 0 and every mole fraction requires division by zero; the calculator must reject this input.
• Negative amounts are physically invalid and must be rejected.
• A zero molar mass causes division by zero in mass-to-mole conversion and must be rejected.
• Incompatible mass and molar-mass units produce incorrect results unless converted first.
• Floating-point rounding can make the displayed Σx differ slightly from 1; the check should use a documented tolerance.

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": {
    "mode": "moles",
    "components": {
      "ethanol": 2,
      "water": 8
    }
  },
  "expected_outputs": {
    "x_ethanol": 0.2,
    "x_water": 0.8,
    "sum_x": 1
  },
  "working": "1. Sum the amounts: Σn = 2.0 mol + 8.0 mol = 10.0 mol. 2. Ethanol: x = 2.0/10.0 = 0.2. 3. Water: x = 8.0/10.0 = 0.8. 4. Check: Σx = 0.2 + 0.8 = 1.0."
}

Other records

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