{ "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-07T09:58:18Z", "providers": [ "Codex", "Grok" ], "missingProviders": [], "pass": 2, "cost": { "grok": { "usd": 0.03877892, "turns": 3, "seconds": 167.6, "error": null }, "codex": { "seconds": 82.6, "error": "Reading additional input from stdin...\nOpenAI Codex v0.153.3\n--------\nworkdir: R:\\02_PROJECTS\\02_Meta_Models_Platforms\\Ver.cy\\current\\thing-registry-backlog\nmodel: gpt-6-astra\nprovider: openai\napproval: never\nsandbox: read-only\nreasoning effort: none\nreasoning summaries: none\nsession id: 01a07b4b-5cf1-7203-9577-0c40b7ff0be9\n--------\nuser\nYou are drafting a Vercy meta-model for one registered thing. Answer as JSON only, no prose around it.\n\nThing: sulfuric acid\nRegistry id: vr.tr.sulfuric-acid\nPlane / domain: PHY / PHY.MAT\nRegistry definition: (none recorded)\nNames folded into this entry: (none" } }, "enrichment": { "pass": 3, "engine": "claude", "producedAt": "2026-10-06T12:00:00Z", "ingestedAt": "2026-10-06T08:13:54+00:00", "fields": [ "agent_conduct", "ethics", "failure_modes_and_hazards", "owners", "standards_and_regulation", "visual_identification" ] }, "gate": { "passed": true, "version": "1.0", "at": "2026-10-07T10:10:30+00:00", "evidence": [ "completeness 1.00", "sense: Wikidata description", "6 live sources", "review by codex: pass" ] } }, "metaModel": { "id": "THING-Q4118", "registryId": "vr.tr.sulfuric-acid", "name": "sulfuric acid", "version": "0.1.0-research.1", "entryKind": "thing", "family": "Thing Registry", "domain": [ "PHY.MAT" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q4118/", "model": { "registry_id": "vr.tr.sulfuric-acid", "name": "sulfuric acid", "purpose": "Enable an AI agent to recognise sulfuric acid, assess a particular material's composition and condition, and determine whether a proposed use or handling action has sufficient supporting evidence.", "definition": "Sulfuric acid is the diprotic sulfur(VI) oxoacid H2SO4, a viscous, nearly non-volatile liquid made almost exclusively by catalytic oxidation of SO2 to SO3 and absorption into concentrated acid (the contact process); it is fully miscible with water with a large exotherm and is traded from dilute aqueous electrolyte through ~93-98% acid and as oleum containing free SO3.", "scope_statement": "This model owns the identity, composition, condition, reactive properties and action constraints of sulfuric acid under vr.tr.sulfuric-acid in PHY.MAT, including aqueous solutions explicitly identified as sulfuric acid; boundaries with oleum, formulated mixtures and spent process streams require explicit classification.", "in_scope": [ "Sulfuric acid identity and evidence connecting a material to H2SO4", "Acid concentration, water content and the basis on which composition is reported", "Grade, impurities and suitability for a specified use", "Physical condition and changes associated with temperature, dilution or contamination", "Compatibility and handling constraints tied to actual composition and operating conditions" ], "out_of_scope": [ "Sulfuric acid manufacturing plants and production process design", "Storage vessels, piping and transfer equipment as engineered assets", "Batteries and other products that contain sulfuric acid", "Sulfate salts, sulfurous acid and sulfur trioxide as independent substances", "Occupational exposure cases, injuries and medical treatment", "Waste treatment facilities and environmental receiving systems" ], "distinguishing_features": [ "Require composition evidence identifying sulfuric acid; low pH or a corrosive label alone does not distinguish it from hydrochloric, nitric or other acids.", "Distinguish sulfuric acid from sulfurous acid through chemical identity evidence rather than similarity of names.", "Distinguish sulfuric acid solutions from sulfate or bisulfate salt solutions by establishing the acid and counterion composition; sulfate detection alone is insufficient.", "Establish water content and any reported free sulfur trioxide before treating a material as ordinary aqueous sulfuric acid rather than oleum.", "Distinguish a sulfuric acid material from a formulated acid mixture or spent process liquor by recording other constituents and their role in determining behavior." ], "characteristics": [ { "name": "Identity evidence", "kind": "relation", "unit_or_values": "Material linked to supplier identity, sample identification and analytical evidence", "why_it_matters": "Connects the registered concept to the actual material being judged." }, { "name": "Sulfuric acid content", "kind": "measurement", "unit_or_values": "Mass percent H2SO4, or another explicitly stated basis with method and uncertainty", "why_it_matters": "Concentration affects suitability, physical behavior and handling constraints." }, { "name": "Water content", "kind": "measurement", "unit_or_values": "Mass percent H2O with measurement or calculation basis", "why_it_matters": "Distinguishes compositions that cannot safely be treated as interchangeable." }, { "name": "Free sulfur trioxide", "kind": "measurement", "unit_or_values": "Mass percent free SO3, with reporting convention and detection limit", "why_it_matters": "Supports the boundary decision between sulfuric acid and oleum." }, { "name": "Temperature", "kind": "measurement", "unit_or_values": "Degrees Celsius with measurement time and location", "why_it_matters": "Physical properties and compatibility judgments require the material's actual temperature." }, { "name": "Density", "kind": "measurement", "unit_or_values": "kg/m3 at a stated temperature", "why_it_matters": "Can support composition checks when the applicable composition model and impurity limits are known." }, { "name": "Physical condition", "kind": "state", "unit_or_values": "Liquid, partly crystallised, solidified, or containing suspended matter; observations dated", "why_it_matters": "Changes in condition may affect sampling, transfer and interpretation of measurements." }, { "name": "Grade and acceptance specification", "kind": "relation", "unit_or_values": "Named grade linked to its actual specification and revision", "why_it_matters": "A grade label alone does not establish fitness for a particular use." }, { "name": "Impurity profile", "kind": "measurement", "unit_or_values": "Constituent-specific mg/kg or mass percent, with methods and detection limits", "why_it_matters": "Contaminants can change suitability, reactions and the reliability of concentration estimates." }, { "name": "Contact compatibility", "kind": "relation", "unit_or_values": "Acid composition linked to contact material, temperature, duration and supporting assessment", "why_it_matters": "A compatibility conclusion is meaningful only for its evaluated conditions." } ], "affordances": [ "Identify a material as sulfuric acid or flag insufficient identity evidence.", "Compare a sample or batch against a specified concentration, grade and impurity requirement.", "Assess whether physical changes or suspected contamination require reassessment.", "Evaluate a proposed storage, transfer or contact arrangement against condition-specific compatibility evidence.", "Check whether dilution or process use is covered by a validated procedure for the actual composition.", "Route uncertain, off-specification or spent material to the appropriate review or waste-stream model." ], "agent_conduct": { "may": [ "Store, label and inventory sulfuric acid according to its safety data sheet.", "Report its hazards and handling precautions from the safety data sheet.", "Monitor storage tanks, levels and leaks at a site that authorized it." ], "must_not": [ "Assist anyone in using sulfuric acid to injure people or damage property.", "Help divert it to illicit drug production or evade controls on its sale.", "Store it in unlabelled, food or drink containers, or where children can reach it.", "Advise handling it without eye, face and skin protection.", "Discharge it to drains or the environment." ], "requires_human": [ "Responding to a spill or leak beyond a minor, contained incident.", "Supplying it to buyers outside normal trade." ] }, "ethics": { "considerations": [ "Acid attacks cause lifelong injury, mostly to women; access must be controlled.", "Spills and emissions harm workers, neighbours and ecosystems." ], "affected_parties": [ "Workers", "People at risk of acid violence", "Communities near plants and transport routes" ] }, "owners": { "steward": "The business or person that holds it; chemical and precursor regulators set the rules for supply.", "master_systems": [ "Chemical inventories and precursor licensing records" ] }, "visual_identification": [ "A colourless to brownish oily liquid, much heavier than water.", "Supplied in containers marked with corrosive hazard pictograms." ], "failure_modes_and_hazards": [ "Causes severe burns to skin and eyes.", "Mixing with water releases heat violently and can spatter.", "Reacts with many metals and chemicals, releasing hazardous gases." ], "standards_and_regulation": [ "Globally Harmonized System of Classification and Labelling of Chemicals, United Nations.", "United Nations Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, 1988, which lists sulfuric acid in Table II." ], "what_it_is_for": [ "Sulfuric acid is used in fertilizer manufacture, mineral processing, petroleum refining and other industrial chemical production.", "It is also encountered as the electrolyte in lead-acid batteries and as a laboratory reagent.", "Its concentration and composition determine its suitability for a particular industrial or analytical application." ] }, "sources": [ { "id": "pubchem", "title": "Sulfuric Acid | H2SO4 | CID 1118", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/sulfuric_acid", "what_it_supports": "Formula, CAS, CID, physical description, commercial grades, GHS H314, uses, and HSDB formulation notes.", "url_status": "live" }, { "id": "govuk", "title": "Sulphuric acid: toxicological overview", "url": "https://www.gov.uk/government/publications/sulphuric-acid-properties-incident-management-and-toxicology/sulphuric-acid-toxicological-overview", "what_it_supports": "Acute and chronic health effects, exposure routes, industrial uses, and carcinogenicity of inorganic acid mists.", "url_status": "live" }, { "id": "cameo", "title": "Sulfuric acid chemical datasheet", "url": "https://cameochemicals.noaa.gov/report?key=CH5193", "what_it_supports": "CAS, UN 1830, DOT corrosive label, NFPA 704 3-0-2-W, and tissue/metal corrosivity.", "url_status": "live" }, { "id": "wikidata", "title": "sulfuric acid (Q4118)", "url": "https://www.wikidata.org/wiki/Q4118", "what_it_supports": "Wikidata item, synonyms, EC number, ECHA infocard, E number, UN 1830, RTECS, HSDB, NIOSH Pocket Guide, and OEL/IDLH values.", "url_status": "live" }, { "id": "ntp", "title": "Strong Inorganic Acid Mists Containing Sulfuric Acid - 15th Report on Carcinogens", "url": "https://www.ncbi.nlm.nih.gov/books/NBK590831/", "what_it_supports": "IARC/NTP carcinogenicity of acid mists (not the bulk liquid), OSHA PEL, ACGIH TLV, NIOSH REL and IDLH.", "url_status": "live" }, { "id": "echa", "title": "Substance Information: sulfuric acid", "url": "https://www.echa.europa.eu/de/substance-information/-/substanceinfo/100.028.763", "what_it_supports": "EC 231-639-5, CAS, REACH/CLP listing and EU occupational-limit listing under the sulphuric spelling.", "url_status": "unverified" }, { "id": "dcceew", "title": "Sulfuric acid - National Pollutant Inventory substance profile", "url": "https://www.dcceew.gov.au/environment/protection/npi/substances/sulfuric-acid", "what_it_supports": "Largest-volume industrial chemical, fertilizer-led uses, melting/boiling points, specific gravity, and mist hazards.", "url_status": "unverified" }, { "id": "wikipedia", "title": "Sulfuric acid", "url": "https://en.wikipedia.org/wiki/Sulfuric_acid", "what_it_supports": "Identifiers (ChEBI, ChemSpider, E513), density, melting/boiling points, pKa2, GHS H290/H314, battery and drain-cleaner uses, and acid-into-water dilution practice.", "url_status": "live" } ], "structure": { "bundles": [ { "id": "identity-and-composition-boundaries", "name": "Identity and composition boundaries", "description": "Establish what material is being represented and whether sulfuric acid is its appropriate primary identity.", "rationale": "Similar names, sulfate-containing materials and acid mixtures can otherwise be assigned sulfuric acid behavior without adequate evidence.", "layers": [ { "id": "chemical-identity", "name": "Chemical identity", "description": "Connect the material's declared identity to evidence about its constituents.", "findings": [ { "id": "supported-sulfuric-acid-identity", "name": "Supported sulfuric acid identity", "description": "Record the basis for identifying sulfuric acid, separating declarations from analytical confirmation.", "questions": [ { "text": "What evidence identifies sulfuric acid in this material rather than another acid or a sulfate salt solution?", "kind": "definition", "id": "supported-sulfuric-acid-identity-q01" }, { "text": "Which supplier record or analysis supports that identity, and which batch or sample does it describe?", "kind": "provenance", "id": "supported-sulfuric-acid-identity-q02" } ] } ] }, { "id": "mixture-boundaries", "name": "Mixture boundaries", "description": "Locate the material relative to aqueous sulfuric acid, oleum and multicomponent process mixtures.", "findings": [ { "id": "primary-model-assignment", "name": "Primary model assignment", "description": "Make explicit whether this model owns the material or describes one constituent of a neighbouring model.", "questions": [ { "text": "Does the reported composition include free sulfur trioxide or other active constituents that require an oleum or formulated-mixture model?", "kind": "boundary", "id": "primary-model-assignment-q01" }, { "text": "If the material is a spent process liquor, what evidence supports retaining sulfuric acid as its primary identity?", "kind": "boundary", "id": "primary-model-assignment-q02" } ] } ] } ] }, { "id": "acid-strength-and-quality", "name": "Acid strength and quality", "description": "Describe composition and quality in terms that support defensible comparison with use requirements.", "rationale": "Sulfuric acid concentration and impurity content must be known beyond labels such as concentrated, dilute or technical grade.", "layers": [ { "id": "concentration-basis", "name": "Concentration basis", "description": "Make acid and water measurements interpretable and comparable.", "findings": [ { "id": "interpretable-acid-assay", "name": "Interpretable acid assay", "description": "Record the concentration convention, method and limitations of the reported acid strength.", "questions": [ { "text": "What are the sulfuric acid and water contents, on what reporting basis, and with what uncertainty?", "kind": "measurement", "id": "interpretable-acid-assay-q01" }, { "text": "Does the assay determine sulfuric acid specifically or total acidity, and what other constituents could affect its interpretation?", "kind": "measurement", "id": "interpretable-acid-assay-q02" } ] } ] }, { "id": "grade-and-impurities", "name": "Grade and impurities", "description": "Relate batch quality to the requirements of a particular application.", "findings": [ { "id": "application-relevant-purity", "name": "Application-relevant purity", "description": "Record the impurity limits and evidence needed for the intended use.", "questions": [ { "text": "Which specification defines this grade, including limits for relevant metals, organics and other contaminants?", "kind": "provenance", "id": "application-relevant-purity-q01" }, { "text": "Which required impurity measurements are available for this batch, and which remain unmeasured?", "kind": "measurement", "id": "application-relevant-purity-q02" } ] } ] } ] }, { "id": "physical-condition-and-change", "name": "Physical condition and change", "description": "Represent the present physical state and evidence of changes since characterisation.", "rationale": "Sulfuric acid property assessments depend on composition and temperature, while handling history can invalidate earlier measurements.", "layers": [ { "id": "condition-at-observation", "name": "Condition at observation", "description": "Tie physical observations and inferred properties to actual measurement conditions.", "findings": [ { "id": "composition-linked-physical-state", "name": "Composition-linked physical state", "description": "Record temperature, phase and observable anomalies without treating appearance as proof of identity.", "questions": [ { "text": "At what temperature was the material observed, and was it liquid, partly crystallised or carrying suspended matter?", "kind": "measurement", "id": "composition-linked-physical-state-q01" }, { "text": "If density is used to infer acid strength, is the reference relationship valid for this temperature and impurity profile?", "kind": "boundary", "id": "composition-linked-physical-state-q02" } ] } ] }, { "id": "composition-change-history", "name": "Composition change history", "description": "Track events that may have altered the material after its last accepted assay.", "findings": [ { "id": "continued-validity-of-characterisation", "name": "Continued validity of characterisation", "description": "Assess whether the recorded composition still represents the material available for use.", "questions": [ { "text": "What exposure to moisture, dilution, process returns or foreign material has occurred since the last assay?", "kind": "provenance", "id": "continued-validity-of-characterisation-q01" }, { "text": "What evidence or acceptance rule determines whether the material needs resampling before its next use?", "kind": "action", "id": "continued-validity-of-characterisation-q02" } ] } ] } ] }, { "id": "reactivity-and-contact-compatibility", "name": "Reactivity and contact compatibility", "description": "Connect sulfuric acid composition and operating conditions to proposed contacts and transformations.", "rationale": "The name sulfuric acid alone cannot establish whether contact with water, another substance or equipment material is acceptable.", "layers": [ { "id": "mixing-and-reaction-context", "name": "Mixing and reaction context", "description": "Capture the evidence required to evaluate dilution, neutralisation and process reactions.", "findings": [ { "id": "evaluated-reactive-contact", "name": "Evaluated reactive contact", "description": "Record whether the proposed contact has been evaluated for heat release, gas generation and other relevant effects.", "questions": [ { "text": "For the actual acid concentration and proposed contacting substance, what evidence establishes the expected heat release, gas generation or oxidation behavior?", "kind": "boundary", "id": "evaluated-reactive-contact-q01" }, { "text": "Which validated procedure covers the proposed dilution or reaction, including its composition and temperature limits?", "kind": "action", "id": "evaluated-reactive-contact-q02" } ] } ] }, { "id": "containment-material-contact", "name": "Containment material contact", "description": "Assess acid compatibility with the materials it will contact.", "findings": [ { "id": "conditional-material-compatibility", "name": "Conditional material compatibility", "description": "Keep compatibility assessments tied to concentration, temperature and service conditions.", "questions": [ { "text": "What evidence supports compatibility with each wetted metal, polymer, lining and seal under the proposed conditions?", "kind": "provenance", "id": "conditional-material-compatibility-q01" }, { "text": "Would dilution, heating or contamination move the acid outside the conditions covered by that assessment?", "kind": "boundary", "id": "conditional-material-compatibility-q02" } ] } ] } ] }, { "id": "use-readiness-and-disposition", "name": "Use readiness and disposition", "description": "Translate sulfuric acid characterisation into a supported decision about use, transfer or reassessment.", "rationale": "An agent needs explicit decision conditions linking acid identity and state to the intended operation.", "layers": [ { "id": "operation-specific-readiness", "name": "Operation-specific readiness", "description": "Determine whether available evidence supports the proposed use of this acid.", "findings": [ { "id": "supported-operation-decision", "name": "Supported operation decision", "description": "Identify the applicable requirements and unresolved gaps for a concrete operation.", "questions": [ { "text": "Does this batch meet the intended operation's acid strength, impurity, temperature and physical-state requirements?", "kind": "action", "id": "supported-operation-decision-q01" }, { "text": "Which handling assessment applies to the actual acid composition and operation, including any potential for splashes or acid mist?", "kind": "provenance", "id": "supported-operation-decision-q02" } ] } ] }, { "id": "off-specification-and-spent-acid", "name": "Off-specification and spent acid", "description": "Represent material that needs reassessment, recovery or transfer to a waste-stream model.", "findings": [ { "id": "evidence-based-disposition", "name": "Evidence-based disposition", "description": "Determine the next responsible disposition without assuming that remaining acidity establishes reusability.", "questions": [ { "text": "What measured departure from the acceptance specification prevents the proposed use?", "kind": "measurement", "id": "evidence-based-disposition-q01" }, { "text": "What additional characterisation is needed to decide between reuse, recovery and handoff to a waste-stream model?", "kind": "action", "id": "evidence-based-disposition-q02" } ] } ] } ] }, { "id": "evidence-and-external-alignment", "name": "Evidence and external alignment", "description": "What the world already says about this thing, gathered so the model can be checked against it.", "rationale": "A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.", "layers": [ { "id": "reported-evidence", "name": "Reported evidence", "description": "Findings from the breadth pass, kept separate from the structural claims.", "findings": [ { "id": "evidence-kinds", "name": "Kinds and varieties", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Dilute / battery-electrolyte acid (typically about 30-40% H2SO4; transport UN 2796 when ≤51%)", "Chamber acid / brown oil of vitriol (~77-80% H2SO4; historical lead-chamber product, still a named trade strength)", "Oil of vitriol / 66° Bé shipping grade (~93% H2SO4; the usual bulk concentration because it freezes low and can be stored in carbon steel)", "Contact-process concentrated acid (about 96-99% H2SO4; the normal plant product and reagent strength)", "Oleum / fuming sulfuric acid (SO3 dissolved in 100% H2SO4; commercial 20-65% free SO3, equivalent acidity >100%)", "Spent / used sulfuric acid (process returns and regenerable waste; distinct UN 1832)", "Reagent, ACS and chemically pure laboratory grades", "Electronic / semiconductor high-purity grade" ], "questions": [ { "id": "evidence-kinds-q01", "text": "Which of these kinds and varieties hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-identifiers", "name": "Identifiers and schemes", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "scheme": "Wikidata", "value_or_pattern": "Q4118", "note": "Item for the chemical compound; aliases include sulphuric acid, battery acid, oil of vitriol." }, { "scheme": "CAS Registry Number", "value_or_pattern": "7664-93-9", "note": "The aqueous acid and the commercial substance; oleum is often the same CAS with a different UN number." }, { "scheme": "EC / EINECS", "value_or_pattern": "231-639-5", "note": "ECHA substance infocard 100.028.763." }, { "scheme": "PubChem CID", "value_or_pattern": "1118", "note": "NCBI PubChem compound record." }, { "scheme": "ChEBI", "value_or_pattern": "CHEBI:26836", "note": "Chemical Entities of Biological Interest." }, { "scheme": "ChemSpider", "value_or_pattern": "1086", "note": "RSC ChemSpider identifier." }, { "scheme": "UN number", "value_or_pattern": "1830", "note": "Sulfuric acid with more than 51% acid; Class 8 corrosive." }, { "scheme": "UN number", "value_or_pattern": "2796", "note": "Sulfuric acid with not more than 51% acid (battery acid)." }, { "scheme": "UN number", "value_or_pattern": "1831", "note": "Oleum / fuming sulfuric acid." }, { "scheme": "UN number", "value_or_pattern": "1832", "note": "Spent sulfuric acid." }, { "scheme": "E number", "value_or_pattern": "E513", "note": "Food acidity regulator in jurisdictions that permit it." }, { "scheme": "RTECS", "value_or_pattern": "WS5600000", "note": "NIOSH Registry of Toxic Effects." }, { "scheme": "HSDB", "value_or_pattern": "1811", "note": "Hazardous Substances Data Bank." }, { "scheme": "NIOSH Pocket Guide", "value_or_pattern": "0577", "note": "Occupational pocket-guide entry." }, { "scheme": "Molecular formula", "value_or_pattern": "H2SO4", "note": "Also written (HO)2SO2 or H2O4S." } ], "questions": [ { "id": "evidence-identifiers-q01", "text": "Which of these identifiers and schemes hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-standards-and-regulation", "name": "Standards and regulation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "UN Model Regulations / ADR / IMDG / 49 CFR: Class 8 corrosive; UN 1830 (>51% acid), UN 2796 (≤51%), UN 1831 (oleum), UN 1832 (spent acid).", "EU CLP Regulation (EC) No 1272/2008, Annex VI harmonised classification: Skin Corr. 1A (H314) and Met. Corr. 1 (H290) as commonly assigned.", "EU REACH (EC) No 1907/2006: registered substance EC 231-639-5.", "EU Indicative Occupational Exposure Limit Values, 3rd list: sulphuric acid listed among IOELVs.", "OSHA PEL 1 mg/m³ (8-hour TWA) for sulfuric acid; legally enforceable US workplace limit.", "NIOSH REL 1 mg/m³ TWA and IDLH 15 mg/m³.", "ACGIH TLV-TWA 0.2 mg/m³ as sulfuric acid in strong inorganic acid mists, thoracic fraction.", "IARC: occupational exposure to strong inorganic acid mists containing sulfuric acid is carcinogenic to humans (Group 1); the classification is of the mist exposure, not of bulk liquid acid as such.", "NTP Report on Carcinogens: strong inorganic acid mists containing sulfuric acid listed as a known human carcinogen.", "GHS/UNRTDG packing group II for UN 1830; NFPA 704 3-0-2 with special W (reacts violently with water)." ], "questions": [ { "id": "evidence-standards-and-regulation-q01", "text": "Which of these standards and regulation hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-real-world-use", "name": "Real-world use", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Largest single use is wet-process phosphoric acid and phosphate fertiliser manufacture.", "Electrolyte in lead-acid batteries (automotive, standby power), typically dilute acid around 30-40%.", "Petroleum refining and alkylation; drying and treating of process streams.", "Steel pickling and other metal cleaning, extraction, electroplating and copper smelting.", "Chemical synthesis: sulfonations and detergent/dye manufacture (often as oleum), mixed-acid nitrations, and as a bulk strong acid.", "Pulp and paper, rayon, pigments, explosives and wood preservatives.", "Domestic acidic drain cleaners at high concentration.", "Laboratory dehydrating and drying agent; chars paper and carbohydrates on contact.", "Present as mist or aerosol from industrial processes and as a component of volcanic gas and acid rain." ], "questions": [ { "id": "evidence-real-world-use-q01", "text": "Which of these real-world use hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-measurements", "name": "Typical measurements", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "quantity": "Mass fraction H2SO4 (aqueous commercial grades)", "typical_range": "battery ~30-40; chamber/BOV ~77-80; shipping 93; contact product 96-99", "unit": "% w/w" }, { "quantity": "Oleum free SO3", "typical_range": "20-65 (CMA standard industrial grades 20, 30, 40, 65)", "unit": "% w/w free SO3" }, { "quantity": "Density of concentrated acid (~93-100%)", "typical_range": "about 1.83-1.84", "unit": "g/cm³" }, { "quantity": "Melting point of 100% H2SO4", "typical_range": "10.3-10.4", "unit": "°C" }, { "quantity": "Boiling point of the ~98.3% acid (azeotrope); 100% decomposes above ~300 °C to SO3 + H2O", "typical_range": "337", "unit": "°C" }, { "quantity": "Molar mass", "typical_range": "98.07-98.08", "unit": "g/mol" }, { "quantity": "Second acidity constant pKa2", "typical_range": "about 2.0 (first proton fully dissociated in water)", "unit": "pKa" }, { "quantity": "Occupational 8-hour TWA (jurisdiction-dependent)", "typical_range": "0.2 (ACGIH thoracic mist) to 1 (OSHA/NIOSH)", "unit": "mg/m³" }, { "quantity": "IDLH", "typical_range": "15", "unit": "mg/m³" }, { "quantity": "Vapour density relative to air", "typical_range": "3.4", "unit": "dimensionless" } ], "questions": [ { "id": "evidence-measurements-q01", "text": "Which of these typical measurements hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-failure-modes-and-hazards", "name": "Failure modes and hazards", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Severe, deep chemical burns to skin and eyes; concentrated acid can cause permanent blindness; a teaspoon to half an ounce of concentrated acid can be fatal if swallowed.", "Violent exotherm and splashing if water is added to concentrated acid; standard practice is acid into water, never the reverse.", "Oleum and hot concentrated acid release SO3 fumes; inhalation of mist causes airway burns, pulmonary oedema and, chronically, bronchitis, tooth-enamel erosion and (as strong inorganic acid mist) laryngeal/respiratory cancer.", "Reacts with most metals, especially when dilute, evolving flammable hydrogen.", "Powerful dehydrating and sulfonating agent: chars organics, can ignite finely divided combustibles, and can explode with chlorates, perchlorates, permanganates, carbides, strong bases and many reductants.", "Concentrated acid is storable in carbon steel; dilution or water ingress switches the system to rapid steel attack and tank failure.", "Oleum freezes or precipitates SO3 in unheated lines (especially high-strength grades), blocking vents and creating overpressure." ], "questions": [ { "id": "evidence-failure-modes-and-hazards-q01", "text": "Which of these failure modes and hazards hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-regional-variation", "name": "Regional variation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Spelling and legal names: sulfuric acid (US, IUPAC, Wikidata default) versus sulphuric acid (UK, many Commonwealth texts, EU IOELV and some ECHA process names).", "Oil of vitriol: in US trade often specifically the ~93%/66° Bé shipping grade; in the UK historically a generic name, with BOV/BBOV (~77-80%) and COV/ROV (~93-96%) as distinct grades.", "Baumé hydrometer degrees remain a US bulk-trade concentration language (60° Bé ≈ 77.7%, 66° Bé ≈ 93.2%); metric % H2SO4 dominates elsewhere.", "Oleum was historically Nordhausen acid in German practice.", "Workplace limits differ: OSHA still 1 mg/m³ PEL; ACGIH and several Canadian provinces use 0.2 mg/m³ thoracic fraction for acid mist; German MAK is reported at 0.1 mg/m³ inhalable.", "E513 as a named food acidity regulator is an EU/Codex-style designation; US food use is as a processing aid under acid listing rather than that E-number." ], "questions": [ { "id": "evidence-regional-variation-q01", "text": "Which of these regional variation hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-neighbours", "name": "Neighbouring kinds and how to tell them apart", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "name": "Hydrochloric acid", "difference": "HCl is a volatile hydrogen halide that fumes in moist air; H2SO4 is essentially non-volatile. Chloride gives AgCl with AgNO3 (soluble in ammonia); sulfate gives acid-insoluble BaSO4 with Ba2+." }, { "name": "Nitric acid", "difference": "HNO3 is a room-temperature oxidizer that evolves brown NOx on metals and organics; concentrated H2SO4 is primarily dehydrating until hot. Nitrate responds to diphenylamine or the brown-ring test; sulfate to BaSO4." }, { "name": "Sulfurous acid / aqueous SO2", "difference": "S(IV) solutions smell of SO2 and reduce oxidants; barium sulfite dissolves in dilute HCl, barium sulfate does not. Oxidation state and the Ba2+/acid test separate them." }, { "name": "Phosphoric acid", "difference": "Weaker triprotic acid used in some of the same metal-treatment roles. Phosphate gives the molybdate yellow/blue test; sulfate gives acid-insoluble BaSO4. Density of concentrated H3PO4 is lower than 1.84 g/cm³ H2SO4." }, { "name": "Oleum (fuming sulfuric acid)", "difference": "Not a different compound family but a different commercial article: free SO3 in 100% H2SO4, fumes in moist air, equivalent acidity >100%, ships as UN 1831 rather than UN 1830." }, { "name": "Battery acid (dilute H2SO4)", "difference": "Same substance at ≤51% H2SO4; density near 1.2-1.3 g/cm³ versus ~1.84 for concentrated acid; transport UN 2796 rather than UN 1830." }, { "name": "Hydrofluoric acid", "difference": "HF etches glass (SiO2) and causes deep, delayed fluoride poisoning treated with calcium gluconate; H2SO4 does not etch silica and is managed as a corrosive mineral acid with irrigation, not calcium chelation." } ], "questions": [ { "id": "evidence-neighbours-q01", "text": "Which of these neighbouring kinds and how to tell them apart hold for the sense of sulfuric acid this model covers, and on what evidence?", "kind": "provenance" } ] } ] } ] } ] }, "openQuestions": [ "Does an existing Vercy world model already own sulfuric acid or any of the proposed solution boundaries?", "Where should the authoritative registry boundary fall between sulfuric acid, oleum, formulated acid mixtures and spent sulfuric acid streams?", "Which analytical methods distinguish sulfuric acid content from total acidity across the compositions this model will cover?", "Which authoritative property and compatibility references provide adequate coverage of concentration, temperature and impurity effects?", "Which intended applications and jurisdictions should supply the initial grade specifications and operation-specific acceptance requirements?" ], "statistics": { "bundles": 6, "layers": 11, "findings": 18, "questions": 28 } }