chemistry.acid_base.henderson_hasselbalch

Three distinct suites: educational examples on the calculator page, this legacy regression count (11/11 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-25.o2-o3.2. Calculation version 1.0.1. CVP 1.0.0-proposed. 4/4 golden · 5/5 CVP boundary · 5/5 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 6/6 CVP contract. digest 2125ba6d5a14. O2: Henderson–Hasselbalch pH vs a separate-module identity (≤2 ULP). Not an ICE table. ≤2 ULP vs O3 applies only to the published tabulated buffer vectors. Not an ICE table.

• Golden (oracle-backed) 4 / 4
• CVP boundary 5 / 5
• Invalid input 5 / 5
• Property 1 / 1
• Metamorphic 1 / 1
• O3 high-precision 8 / 8
• Cross-interface 2 / 2
• CVP contract 6 / 6
• Interfaces PASS · UI (SSR) / REST / MCP
• Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
• Verified scope Buffer pH = pKa + log10(A/HA), with pKa or Ka, + O3 mpmath tabulated buffer pH.
• Assurance Engineering
• Deferred Not an ICE table and not pH = −log10[H+].

• release artifacts aligned PASS
• schema output required declared PASS
• schema valid input executes PASS
• engine success output validates schema PASS
• schema rejects incomplete input PASS
• rest success payload validates schema PASS

Fingerprint sha256:247d67238603e25e60952acb7369fae6eb21d102d14e49cea9113f1aa3cdea16

Input schema sha256:ce20f2f51db961b2a4bd21752670c34893549d02faec96c6656120eeb6fd182d · Output schema sha256:d189af345059376b65ecb82ca089cbab82a24806606b6254ab32d8c14641a0d4 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Tool

henderson-hasselbalch

Engine

henderson-hasselbalch

Engine build

2026-09-25

Evidence core

2026-09-25T00:17:40.683Z

Rendered

2026-10-23T01:27:11.351Z

Last reviewed

—

Assumptions

• Monoprotic buffer; HA and A− are the pair as given
• Activity coefficients ≈ 1
• Not ICE equilibrium
• Not pH = −log10[H+]
• Not polyprotic

Limitations

• Monoprotic buffer pair as given — not ICE equilibrium
• Not pH = −log10[H+]
• Not activity coefficients or polyprotic