n-pentane
Enable an AI agent to identify n-pentane, assess the condition and suitability of a particular sample, and determine which uses or handling actions require further evidence.
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 AI agent to identify n-pentane, assess the condition and suitability of a particular sample, and determine which uses or handling actions require further evidence.
n-Pentane is the unbranched constitutional isomer of the saturated hydrocarbon C5H12, with structure CH3(CH2)3CH3, occurring as a volatile, highly flammable liquid at ordinary room temperature and atmospheric pressure.
It can be Resolve an ambiguous pentane label against molecular identity and analytical evidence.; Compare a sample's assay and impurity profile with a use-specific specification.; Interpret or estimate phase and volatility within a documented temperature-pressure range.; Assess whether a documented grade is suitable for a specified solvent, reference-material, or evaporation-dependent use.; Derive handling and storage requirements from verified hazard information and actual sample conditions.; Flag samples for further analysis when provenance, contamination, or evaporative loss undermines their stated grade..
Distinguishing features
Its molecular connectivity is CH3-CH2-CH2-CH2-CH3; a branched five-carbon skeleton identifies a different pentane isomer.
Its molecular formula is C5H12; formula alone cannot distinguish it from isopentane or neopentane.
A designation of 'pentane' without structural or analytical evidence does not establish that a sample is n-pentane rather than an isomer mixture.
A sample identified as predominantly n-pentane still requires an assay and impurity profile before it can be treated as a particular purity grade.
Observed volatility or a boiling range can support identification but cannot alone establish molecular identity or exclude a pentane blend.
Scope
+ Molecular identity and distinction from other pentane isomers
+ Sample purity, grade, impurities, and analytical evidence
+ Phase, volatility, and measured properties under stated conditions
+ Suitability as a solvent, reference material, or volatile process input
+ Substance-specific hazard evidence, storage constraints, and jurisdictional identity
- Isopentane and neopentane as separate substances
- Petroleum fractions, commercial pentane blends, and formulated products as whole mixtures
- Manufacturing and separation processes as operational systems
- Containers, ventilation equipment, and fire-protection systems as engineered assets
- Finished foams, extracts, fuels, or other products made using n-pentane
Characteristics
- Molecular identity
- C5H12; unbranched connectivity CH3-CH2-CH2-CH2-CH3 Separates n-pentane from its branched constitutional isomers.
- Registry identifier alignment
- vr.tr.n-pentane linked to verified CAS, PubChem, and EC records Prevents identifiers for mixtures or other isomers from being attached to this substance.
- n-Pentane assay
- Mass fraction, mole fraction, or method-defined chromatographic area percentage Establishes sample composition without treating different reporting bases as interchangeable.
- Impurity profile
- Individual impurity concentrations in mg/kg or stated fraction, with detection limits Other hydrocarbons, water, and residues can change suitability even when the headline assay is acceptable.
- Grade and specification
- Supplier grade, specification revision, acceptance limits, and certification status A grade name alone does not establish fitness for an analytical or industrial use.
- Sample phase and conditions
- Solid, liquid, vapor, or multiphase; temperature in °C or K; absolute pressure in kPa Phase and conditions determine how the sample can be measured, transferred, and interpreted.
- Phase-transition properties
- Melting/freezing temperature and boiling temperature or range in °C or K, with pressure and purity Supports identity checks and operating limits while separating reference values from batch measurements.
- Vapor pressure
- kPa at a stated temperature, with measurement source or correlation validity range Supports assessment of evaporation, vapor generation, and containment requirements.
- Density
- kg/m³ at stated temperature, pressure, phase, and composition Supports mass-volume conversion and sample consistency checks.
- Application performance
- Target material or process linked to measured solubility, evaporation, residue, or expansion requirements Makes suitability depend on the intended application and evidence for this grade.
- Applicable hazard classification
- Verified hazard classes, categories, statements, jurisdiction, source, and revision date Connects handling decisions to applicable evidence for the substance or supplied sample.
- Sample traceability and integrity
- Lot identity, certificate linkage, opening history, storage history, and integrity assessment Distinguishes a documented sample from one whose composition or condition is uncertain.
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 19 findings · 29 questions.
Molecular identity and boundaries Establishes which chemical entity the name n-pentane denotes and whether a supplied sample belongs under it.
Pentane isomers share a molecular formula, and commercial naming can obscure the distinction between n-pentane and pentane mixtures.
Unbranched isomer
Captures the connectivity that distinguishes n-pentane.
Straight-chain identity
Identity depends on the unbranched five-carbon structure, rather than the molecular formula alone.
- Does the identity record explicitly describe CH3-CH2-CH2-CH2-CH3 rather than either branched C5H12 isomer? definition
- Which structural or analytical evidence distinguishes this sample from isopentane, neopentane, and their mixtures? measurement
Identifiers and mixture boundary
Aligns registry records and sets the boundary between the substance and a supplied mixture.
Name-to-substance resolution
External identifiers and supplier terminology require verification against the unbranched substance.
- Which authoritative records verify the CAS number, PubChem CID, and EC number for n-pentane? provenance
- Does the supplied material represent an n-pentane grade with specified impurities or a pentane blend requiring its own mixture model? boundary
Composition, grade, and evidence Describes what a particular n-pentane sample contains and how its stated grade is supported.
Isomer content, water, and nonvolatile residues can matter independently of the nominal n-pentane purity.
Assay and impurities
Records composition on an explicit analytical basis.
Composition resolution
The model must distinguish a reported n-pentane assay from evidence that resolves relevant impurities.
- What is the n-pentane content, on which reporting basis, and with what uncertainty or method limitation? measurement
- Which method quantifies other pentane isomers, neighboring hydrocarbons, water, and nonvolatile residue, and what are its detection limits? measurement
Grade and lot provenance
Connects stated specifications to the actual sample and its history.
Grade evidence chain
Suitability requires a traceable specification and sample-specific evidence, with changes since certification considered.
- Which lot-linked certificate and specification revision support the claimed n-pentane grade? provenance
- Have opening, transfer, storage, or suspected evaporative loss created a need to reassess composition before use? action
Phase and volatility Relates n-pentane's physical state and measurable properties to temperature, pressure, and composition.
Its use and handling depend on phase behavior and vapor generation, so unqualified property values are insufficient.
Phase envelope
Records observed phase and the conditions associated with phase transitions.
Conditioned phase properties
Reference transition temperatures must be separated from measurements on potentially impure samples.
- What phase or phases are present at the sample's measured temperature and absolute pressure? measurement
- Which sources establish melting and boiling values, including pressure, purity, method, and uncertainty? provenance
Vapor and liquid properties
Supports interpretation of evaporation and liquid inventory.
Valid property use
Vapor-pressure and density data require explicit conditions and a valid range before supporting decisions.
- Which vapor-pressure measurements or correlation apply across the intended operating temperatures? measurement
- What density applies to this sample's composition and temperature when converting between liquid volume and mass? measurement
Application fitness Links n-pentane properties and grade to a specified role.
Solvent behavior, clean evaporation, reference-material quality, and vapor-generation performance impose different requirements.
Solvent and analytical use
Tests whether a grade supports the required dissolution, separation, or analytical function.
Use-specific acceptance
A solvent or analytical role needs explicit acceptance criteria for the target method and materials.
- What evidence establishes adequate solubility or partitioning for the target substances at the intended temperature? measurement
- Which limits on interfering hydrocarbons, water, residue, or certification must this n-pentane grade meet before the intended method can use it? action
Evaporation-dependent use
Assesses roles that depend on n-pentane leaving a liquid phase or generating vapor.
Volatility performance boundary
Evaporation-dependent applications require evidence connecting sample properties to process requirements.
- Which measured evaporation, boiling-range, residue, or vapor-generation requirements determine whether this grade is acceptable? measurement
- Which performance claims belong to the n-pentane sample, and which require a separate model of the formulation, equipment, or finished product? boundary
Hazards and handling constraints Collects verified hazard evidence and translates it into conditions for sample handling.
Decisions involving n-pentane vapor, exposure, storage, and disposal need current sources applicable to the supplied material and jurisdiction.
Classification and exposure
Establishes the applicable classification and exposure criteria without assuming that every supplier record is equivalent.
Applicable hazard record
Hazard and exposure records must identify their substance scope, jurisdiction, and revision.
- Which current authoritative classification and safety data sheet establish the applicable physical, health, and environmental hazards for this material? provenance
- Which occupational exposure limits apply, including averaging periods, units, jurisdiction, and whether their scope is n-pentane specifically or a broader pentane category? measurement
Handling and storage decisions
Relates sample conditions and verified safety properties to permitted handling actions.
Evidence-based handling
Handling decisions require verified ignition, compatibility, exposure, and containment information for the proposed operation.
- Which verified flash-point, flammability-limit, ignition, and incompatibility data constrain the intended temperature, transfer method, and nearby materials? provenance
- What ventilation, ignition control, containment, storage, and waste-routing requirements follow from those data and the actual quantity and conditions? 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.
- This is recalled information, with no sources consulted; numerical properties are approximate values for the pure substance.
- Verify current jurisdiction-specific classifications, exposure limits and transport requirements before operational use.
- Grade names are supplier-dependent; verify assay, isomer content, water and nonvolatile residue against the product specification.
- Which of these check these first hold for the sense of n-pentane this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Technical-grade n-pentane
- Reagent-grade n-pentane
- Chromatography-grade n-pentane
- Which of these kinds and varieties hold for the sense of n-pentane 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 - 109-66-0 - Identifies n-pentane specifically, rather than pentane isomer mixtures.
- PubChem CID - 8003 - Compound identifier for n-pentane.
- EC number - 203-692-4 - European substance inventory identifier.
- SMILES - CCCCC - Encodes the unbranched five-carbon chain.
- Which of these identifiers and schemes hold for the sense of n-pentane this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS): framework for chemical hazard classification and communication.
- European Union REACH Regulation: substance registration and chemical supply-chain obligations.
- European Union CLP Regulation: classification, labelling and packaging of substances and mixtures.
- US Occupational Safety and Health Administration Hazard Communication Standard: workplace chemical labels and safety data sheets.
- Which of these standards and regulation hold for the sense of n-pentane this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Nonpolar solvent for extraction and laboratory procedures.
- Solvent component in chromatography.
- Physical blowing agent in polymer foam manufacture.
- Working fluid in some organic Rankine cycle systems.
- Component of gasoline and light petroleum fractions.
- Which of these real-world use hold for the sense of n-pentane 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 - 72.15 - g/mol
- Normal boiling point at 101.325 kPa - Approximately 36.1 - °C
- Melting point - Approximately -129.7 - °C
- Liquid density at approximately 20 °C - Approximately 0.626 - g/cm³
- Vapour pressure at approximately 20 °C - Approximately 57 - kPa
- Which of these typical measurements hold for the sense of n-pentane 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.
- Readily produces ignitable vapour at room temperature; vapour-air mixtures can burn or explode.
- Vapour is denser than air and can accumulate in low areas or travel to an ignition source.
- Inhalation at elevated concentrations can cause dizziness, drowsiness and central nervous system depression.
- Aspiration into the lungs following ingestion or vomiting can cause severe chemical lung injury.
- Repeated skin contact can remove skin oils and cause dryness or irritation.
- Which of these failure modes and hazards hold for the sense of n-pentane this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Occupational exposure limits and their averaging periods differ between jurisdictions and issuing bodies.
- Required labels and safety data sheet classifications depend on the jurisdiction's implementation of chemical hazard rules.
- Which of these regional variation hold for the sense of n-pentane 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.
- Isopentane - Has the same molecular formula but a branched 2-methylbutane structure.
- Neopentane - Has the same molecular formula but the more highly branched 2,2-dimethylpropane structure.
- Cyclopentane - Has a five-carbon ring and formula C5H10 rather than the open-chain formula C5H12.
- Commercial pentane mixtures - Contain multiple components or pentane isomers; their composition and properties cannot be assigned those of pure n-pentane.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of n-pentane this model covers, and on what evidence? provenance
What the second pass must settle
- Which authoritative identity records should anchor the CAS, PubChem, and EC mappings for vr.tr.n-pentane?
- Which measured property sources provide defensible melting point, boiling point, vapor pressure, and density values with conditions and uncertainty?
- Which recognized or supplier-specific grade specifications distinguish relevant n-pentane uses, and which impurity limits materially affect each use?
- Which current jurisdictional classifications and exposure limits apply specifically to n-pentane, and where do sources instead cover pentanes or mixtures?
- What evidence and local catalogue convention determine when a supplied pentane composition remains an n-pentane grade versus requiring a separate mixture record?