Source: https://guthlabs.ai/docs/instruments/arrhenius-equation-calculator/

instrument / verified-with-binding-errata

# Arrhenius Equation Calculator

The current ledger marks this instrument verified with errata that must be applied at binding time.

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

## Inspectable records

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

## Ledger state

The current ledger marks this instrument verified with errata that must be applied at binding time.

**Area**: Chemistry & Materials

**Tranche**: tranche-4

**Evidence ID**: t4-298

**Ledger rows**: 1

No ledger note is attached.

## Review findings

NEEDS_REVIEW because the formulas themselves are standard, but the input-combination rules, inverse-solver behavior, temperature units, and positivity constraints are unspecified. The original two-temperature test construction was corrected in the working so all reported final expected outputs are mathematically consistent.

### Formula and scope findings

- The two displayed equations are standard Arrhenius formulas, but the specification does not define the inverse rearrangements needed to calculate Ea or A from the supplied variables.

- The claim that inputs may be 'any combination' is underdetermined: a unique result requires sufficient independent inputs, such as A, Ea, and T for k; k, A, and T for Ea; or k, Ea, and T for A.

- The two-temperature form requires two complete temperature-rate pairs and a declared direction for the ratio; this constraint is not specified.

### Unit assumptions

- Use absolute temperature in kelvin: T > 0 K. Celsius or Fahrenheit inputs must be converted before calculation.

- Use R = 8.314462618 J mol^-1 K^-1 unless another value is explicitly selected.

- Ea and R must use matching energy units; the test calculations use Ea in J/mol.

- k and A must use compatible units, commonly s^-1 for first-order kinetics; the ratio k2/k1 is dimensionless.

- The exponential argument -Ea/(RT) must be dimensionless.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

The specification permits arbitrary combinations without stating validation behavior. Equal temperatures with unequal rate constants produce an undefined activation energy, and an unspecified temperature unit produces materially different results. The calculator should reject singular inputs and require absolute temperature in kelvin.

## Errata and corrections

### Tranche errata

**k2, k2_over_k1** · vector 4

k2 200 (ratio 2) with Ea 1728.9439

with given Ea: k2 = 141.42 (ratio √2); or Ea must be 3457.888 for ratio 2

vector designed with T=300 in Ea instead of harmonic 600; her own working NOTICED the inconsistency and shipped anyway

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "A_s^-1": 250000000000,
    "Ea_J_per_mol": 0,
    "T_K": 298.15
  },
  "expected_outputs": {
    "k_s^-1": 250000000000
  },
  "working": "k = A·e^(-Ea/(RT))\n= 250000000000·e^(-0/(8.314462618·298.15))\n= 250000000000·e^0\n= 250000000000·1\n= 250000000000 s^-1"
}
````

## Related workflows

[Reaction Energetics Benchkinetics](<https://guthlabs.ai/docs/instrument-workflows/reaction-energetics/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_WITH_ERRATA`

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

- `BOUNDARY_HAZARD_CATALOG.json`