Ka/Kb ⇄ pKa/pKb Converter 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

t4-039

Effect

Computation or source lookup only

Input and validation requirements

• Ka=0 or Kb=0 causes division by zero when deriving the conjugate constant and makes the logarithm undefined.
• Negative Ka, Kb, or Kw values are invalid for these logarithms and equilibrium-constant calculations.
• The implementation must reject missing, nonnumeric, NaN, infinite, zero, or negative equilibrium constants when logarithms or reciprocal conversions are required.
• Using a default Kw without displaying or documenting its temperature can produce materially incorrect results.
• Inputs with concentration units are an ambiguity or unit-conversion trap unless the standard-state convention is explicitly defined.

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": {
    "Ka": 0.00001
  },
  "expected_outputs": {
    "Ka": 0.00001,
    "pKa": 5,
    "Kb": 1e-9,
    "pKb": 9
  },
  "working": "1. pKa=-log10(1×10^-5)=5. 2. Kb=Kw/Ka=(1×10^-14)/(1×10^-5)=1×10^(-14+5)=1×10^-9. 3. pKb=-log10(1×10^-9)=9."
}

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