Source: https://guthlabs.ai/docs/instruments/standard-reduction-potential-activity-series-lookup/implementation/

instrument implementation / implementation-contract

# Standard Reduction Potential / Activity Series Lookup implementation

A source-bound implementation contract for Standard Reduction Potential / Activity Series Lookup; 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**: t6-108

**Effect**: Computation or source lookup only

## Input and validation requirements

An unrecognized species such as X3+/X produces an undefined lookup result. The instrument must explicitly reject it; otherwise downstream comparison and reaction prediction can propagate undefined or fabricated values.

## 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": {
    "cathode_candidate": "Cu2+ + 2e− ⇌ Cu(s)",
    "cathode_E0_V": 0.34,
    "anode_candidate": "Zn2+ + 2e− ⇌ Zn(s)",
    "anode_E0_V": -0.76
  },
  "expected_outputs": {
    "E0_values_V": {
      "Cu2+/Cu": 0.34,
      "Zn2+/Zn": -0.76
    },
    "reduced_species": "Cu2+",
    "oxidized_species": "Zn(s)",
    "balanced_reaction": "Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)",
    "E0_cell_V": 1.1,
    "standard_spontaneity": "spontaneous in the written direction"
  },
  "working": "Compare 0.34 V and −0.76 V: 0.34 V is more positive, so Cu2+ is reduced. Reverse the zinc reduction: Zn(s) → Zn2+ + 2e−. Add the half-reactions: Zn(s) + Cu2+ → Zn2+ + Cu(s). E°cell = E°cathode − E°anode = 0.34 − (−0.76) = 0.34 + 0.76 = 1.10 V. Since 1.10 V > 0, the reaction is standard-state spontaneous."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/standard-reduction-potential-activity-series-lookup/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/standard-reduction-potential-activity-series-lookup/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/standard-reduction-potential-activity-series-lookup/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`