picric acid
Enable an agent to identify picric acid, assess the condition of a particular sample, and determine which uses or interventions require verified evidence and specialist authorization.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to identify picric acid, assess the condition of a particular sample, and determine which uses or interventions require verified evidence and specialist authorization.
Picric acid is 2,4,6-trinitrophenol, a yellow crystalline organic compound with formula C6H3N3O7 whose nitro substituents confer pronounced phenolic acidity and explosive properties.
It can be Reconcile a label, supplier record, and analytical report against the identity of picric acid.; Compare assay and water-content results using compatible reporting bases.; Assess whether composition and condition records support a specified analytical or laboratory use.; Flag undocumented drying, deposits, incompatible contacts, or uncertain condition for specialist assessment.; Retrieve classifications and exposure constraints applicable to the particular sample and jurisdiction.; Record an authorized use or specialist disposition decision with its supporting evidence..
Distinguishing features
Structural identification must establish a phenol bearing nitro groups at positions 2, 4, and 6; another nitrated aromatic compound does not satisfy this identity.
Distinguish the parent acid from a picrate salt by recording ionic form and any counterion.
Distinguish picric acid from trinitrotoluene by the phenolic hydroxyl group rather than a methyl substituent.
A wetted solid or solution must retain its water or solvent content in its sample description; the substance name alone does not establish composition or condition.
Appearance and labeling provide supporting evidence but cannot independently establish identity, purity, or safe condition.
Scope
+ Molecular identity and verified chemical registry identifiers
+ Grade, purity, impurities, and analytical evidence
+ Dry, wetted, dissolved, or otherwise formulated sample condition
+ Condition-dependent properties and hazards
+ Container compatibility, deterioration, and inspection evidence
+ Application suitability and jurisdiction-specific handling constraints
- Picrate salts as independently identified chemical substances
- Complete formulations of stains, fixatives, dyes, or other products containing picric acid
- Manufacturing, synthesis, purification, or energetic processing procedures
- Explosive devices and their design or performance
- Facility emergency response and hazardous-waste treatment procedures
- Clinical diagnosis and treatment of chemical exposure
Characteristics
- Chemical identity
- 2,4,6-trinitrophenol; molecular formula C6H3N3O7; verified structure and identifiers Separates picric acid from related nitrophenols, other nitrated aromatics, and mislabeled materials.
- Acid or picrate form
- Parent acid; dissolved acid/picrate equilibrium; identified picrate salt; unresolved Prevents salts and solution speciation from being treated as interchangeable with the parent substance.
- Assay and reporting basis
- Mass percent with as-received or dry-basis designation, method, and uncertainty Distinguishes chemical purity from dilution or intentional wetting.
- Water and solvent content
- Mass percent or explicitly defined concentration units; component identity; measurement date Supports assessment of the actual sample and whether its documented condition remains current.
- Physical condition
- Wetted solid; dry solid; solution; visible deposits; heterogeneous material; unknown Different conditions require different evidence and handling decisions.
- Thermal behavior
- Degrees Celsius with event type, sample composition, method, and decomposition qualification Prevents melting, decomposition, and boiling information from being conflated.
- Solution acidity
- pH with solvent, concentration, temperature, and method Acidity is a property of a specified solution rather than an unconditional value for the substance.
- Container and closure compatibility
- Contact materials linked to compatibility evidence and inspection observations Contact materials and possible picrate formation can affect the condition assessment.
- Hazard and regulatory classification
- Classification system, jurisdiction, product condition, source, and revision date A classification must match the actual composition and governing context.
- Disposition status
- Awaiting assessment; authorized for specified use; restricted; referred for specialist disposition Connects evidence and uncertainty to an explicit decision without assuming that identification establishes usability.
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.picric-acid
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 17 findings · 27 questions.
Picric acid identity Establishes the parent substance and its boundary with related compounds and picrate salts.
Similar names, shared nitro groups, and acid-derived salts do not establish equivalent chemical identity.
Molecular identification
Connects the registered thing to a verified molecular structure.
2,4,6-trinitrophenol identity
Recognition requires evidence supporting the phenolic structure and the positions of its three nitro groups.
- Which structural definition establishes this material as 2,4,6-trinitrophenol? definition
- Which authoritative records verify its CAS number, PubChem CID, and EC number? provenance
Acid and salt boundary
Distinguishes the parent acid, solution speciation, and separately identified salts.
Picrate distinction
The record must distinguish an isolated picrate salt from picric acid and describe solution speciation when relevant.
- Does the material represent the parent acid, an identified salt, or a solution containing acid and picrate species? boundary
- What evidence identifies any counterion or supports the reported solution speciation? provenance
Assay and wetting Describes how much picric acid is present and what accompanies it.
Purity, concentration, and wetting are distinct attributes that jointly determine sample interpretation.
Grade and impurities
Captures the evidence behind a grade or assay claim.
Assay basis
An assay requires a reporting basis and method so that water or solvent is not mistaken for chemical impurity.
- What assay was measured, by which method, and on an as-received or dry basis? measurement
- Which impurities were assessed, and what specification supports the claimed grade? provenance
Water, solvent, and uniformity
Describes the sample's diluent or wetting medium and the currency of that evidence.
Documented wetting state
A wetted-material designation needs supporting composition evidence and cannot be assumed current indefinitely.
- What water or solvent content is documented, with which units, method, and date? measurement
- What evidence addresses evaporation, uneven wetting, or a difference between the bulk material and visible deposits? provenance
Condition-dependent properties Relates physical and chemical measurements to the specific form of picric acid assessed.
Values for a pure solid, wetted material, and solution cannot be applied interchangeably.
Phase and thermal events
Records physical form and qualified thermal-property evidence.
Qualified thermal properties
Thermal records must identify the observed event and whether decomposition limits the interpretation of a reported constant.
- Which physical form and composition does each melting or thermal-event value describe? measurement
- Does the source establish a boiling point, report decomposition, or leave boiling behavior unresolved? provenance
Solution properties
Captures solubility and acidity under specified conditions.
Solubility and acidity context
Solution-property claims require solvent, temperature, concentration, and a distinction between measured and inferred results.
- What solubility is supported for the specified solvent and temperature? measurement
- What concentration, temperature, and method accompany any pH or acid-dissociation value? measurement
Sample hazards and compatibility Connects picric acid's hazard assessment to wetting, contamination, and container condition.
A substance-level name or an old supplier document cannot by itself establish the current condition of a container.
Drying and deposits
Addresses evidence of condition changes that require specialist interpretation.
Condition-change escalation
Unknown wetting status, suspected drying, or deposits must be represented as unresolved conditions rather than presumed acceptable.
- What existing inspection evidence records suspected drying, deposits, leakage, or an unreadable condition label? provenance
- Which qualified assessment is required before any handling decision when those conditions are unresolved? action
Contact materials and picrates
Examines container contacts and possible contamination without inferring composition from appearance.
Compatibility evidence
Container bodies, closures, and known contaminants require compatibility evidence specific to picric acid and possible picrate formation.
- Which container and closure materials contact the sample, and what source establishes their compatibility? provenance
- Is possible picrate formation documented, suspected, or unassessed, and what specialist decision follows? action
Use and regulatory disposition Determines whether a specified sample has sufficient evidence for an intended use or disposition.
Picric acid's grade, formulation, condition, and jurisdiction all affect what an agent may authorize or recommend.
Application fit
Relates sample specifications to a documented application while preserving the boundary with formulated products.
Specified-use eligibility
Suitability must follow an application specification rather than the substance name or historical use alone.
- Which intended application defines acceptable assay, impurities, solvent, and condition? action
- Does the decision concern picric acid itself or a stain, fixative, or other formulation requiring a separate model? boundary
Classification and disposition
Links current regulatory evidence and accountable decisions to the actual material.
Condition-specific controls
Hazard, transport, exposure, and waste records must identify their jurisdiction, date, and applicability to the documented composition.
- Which current sources establish the applicable GHS classification, transport identity, and occupational exposure limits for this material and jurisdiction? provenance
- Who has authorized the specified use or specialist disposition, and which condition evidence supports that decision? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- These statements are recalled knowledge; no sources were consulted.
- Verify numerical constants against references specifying purity, temperature and measurement conditions.
- Transport classification, hazard labeling and exposure limits require verification for the jurisdiction and the preparation's water content and concentration.
- Which of these check these first hold for the sense of picric acid this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Anhydrous crystalline picric acid
- Water-wetted picric acid
- Analytical-reagent-grade picric acid
- Which of these kinds and varieties hold for the sense of picric acid this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- CAS Registry Number - 88-89-1 - Identifies picric acid; solutions and preparations require additional composition information.
- PubChem CID - 6954 - Recalled identifier for picric acid.
- Chemical nomenclature - 2,4,6-trinitrophenol - Specifies the positions of the three nitro groups on the phenol ring.
- Which of these identifiers and schemes hold for the sense of picric acid this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Historical military explosive and shell filling.
- Component of certain histological fixatives, including Bouin's solution.
- Reagent in the alkaline picrate, or Jaffé, method for measuring creatinine.
- Component of some metallographic etchants.
- Historical yellow dye.
- Which of these real-world use hold for the sense of picric acid this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Molar mass - 229.10 - g/mol
- Melting point of the pure substance - Approximately 122-123 - °C
- Acid dissociation constant, pKa in water - Approximately 0.4; dependent on measurement conditions - dimensionless
- Which of these typical measurements hold for the sense of picric acid this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Dry picric acid is explosive and can respond dangerously to heat, shock or friction.
- Loss of water from wetted material can increase its sensitivity.
- Contact with certain metals or metal compounds can form picrate salts that are more sensitive than the parent acid.
- Toxic exposure can occur through ingestion, inhalation or skin absorption.
- Dried residues around container closures can present a localized explosive hazard.
- Which of these failure modes and hazards hold for the sense of picric acid this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Phenol - Picric acid has three nitro substituents at positions 2, 4 and 6; phenol has none.
- Picrate salts - These contain the deprotonated picrate anion paired with a cation, rather than neutral picric acid.
- Trinitrotoluene - TNT has a methyl group where picric acid has a hydroxyl group and lacks its phenolic acid functionality.
- Bouin's solution - This is a formulated fixative containing picric acid and other components, not the individual substance.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of picric acid this model covers, and on what evidence? provenance
What the second pass must settle
- Which authoritative identity records verify the CAS number, PubChem CID, and EC number, and distinguish the parent acid from wet formulations and picrate salts?
- Which measured melting, decomposition, solubility, and acid-dissociation values are reliable, and under what conditions are they applicable?
- Which current sources establish condition-dependent hazard and transport classifications, including the role of water content?
- Which jurisdiction-specific occupational exposure limits and annotations apply to the intended setting?
- What evidence is sufficient to establish the present condition and application suitability of an aged sample with uncertain wetting or container history?