Nernst Equation Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Chemistry & Materials

Tranche

tranche-4

Evidence ID

t4-265

Ledger rows

1

No ledger note is attached.

Review findings

The instrument should not be honestly labeled as computing E from arbitrary ion concentrations until it requires or defines the balanced cell reaction, stoichiometric exponents, activities or an ideal concentration approximation, and reaction orientation. It should also distinguish the exact temperature-dependent RT/nF form from the approximate 25 °C 0.0592 form. The CODATA R version and the chosen F precision should be fixed for reproducible results.

Formula and scope findings

• The algebraic Nernst formulas are standard and correct, but 'Q or ion concentrations' is ambiguous because the reaction stoichiometry and the mapping from concentrations to Q are not specified.
• Q must be the dimensionless reaction quotient formed from activities (or concentration ratios under an explicitly stated ideal-solution approximation); raw concentrations cannot universally be substituted directly.
• The 0.0592 coefficient is an approximation valid for base-10 logarithms at 25 °C (298.15 K), not at an arbitrary temperature.
• The sign and definition of Q depend on the specified cell-reaction orientation, which is not provided.

Unit assumptions

• E° and E are in volts.
• n is a positive, dimensionless electron-transfer count.
• T in E=E°-(RT/nF)ln Q is absolute temperature in kelvins; Celsius must be converted using T_K=T_°C+273.15.
• R is 8.314462618 J mol^-1 K^-1 and F is 96485 C mol^-1 for the test calculations.
• Q is dimensionless and is constructed from activities relative to the standard state.
• The 0.0592/n coefficient uses log base 10 and assumes T=298.15 K; the more precise value is approximately 0.05916 V per electron.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The input n=0 produces division by zero in the Nernst correction term, so the calculator must reject it rather than return a numeric potential. The specification does not state an explicit validation rule for this case.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

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

{
  "inputs": {
    "E°_V": 1.1,
    "n": 2,
    "Q": 0.01,
    "T_K": 298.15,
    "formula": "E=E°-(RT/nF)ln Q"
  },
  "expected_outputs": {
    "E_V": 1.15916
  },
  "working": "R T/F = (8.314462618 J mol^-1 K^-1 × 298.15 K)/(96485 C mol^-1) = 0.02569267 V. Therefore RT/(nF)=0.02569267/2=0.01284633 V. ln(0.01)=-4.60517019. E=1.10-(0.01284633×-4.60517019)=1.10+0.05915955=1.15915955 V, approximately 1.15916 V."
}

Related workflows

Sources and evidence

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

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json