Molar Mass of Hexane (C₆H₁₄)
Learn how chemists calculate the molar mass of Hexane (C₆H₁₄), with a clear formula breakdown, worked steps, and study notes.
Quick answer
The molar mass of Hexane (C₆H₁₄) is
86.178g/mol
One mole of Hexane therefore has a mass of 86.178 grams—the value you use for stoichiometry and laboratory preparation.
Reviewed for educational accuracy · Accuracy policy
- CAS Registry Number
- 110-54-3
- PubChem CID
- 8058
- SMILES
- CCCCCC
Step-by-step calculation
Let's find the molar mass of Hexane (C₆H₁₄) together—step by step, as if you are seeing the formula for the first time.
Step 1 — Look at the chemical formula
The formula is C₆H₁₄. Each letter stands for an element. The little number after a letter (the subscript) tells you how many atoms of that element are in one molecule or formula unit.
- 6 Carbon atoms (C)
- 14 Hydrogen atoms (H)
Step 2 — Look up each atomic mass
Atomic mass comes from the periodic table. It is the average mass of one mole of atoms of that element, in grams per mole (g/mol). Think of it as the "price tag" for one mole of that element.
- Carbon (C) = 12.011 g/mol
- Hydrogen (H) = 1.008 g/mol
Step 3 — Multiply atoms × atomic mass
Why multiply? If one oxygen atom "costs" about 16 g/mol, then two oxygen atoms cost twice as much. Each element's contribution is: number of atoms × atomic mass.
- 6 × 12.011 = 72.066 g/mol (Carbon)
- 14 × 1.008 = 14.112 g/mol (Hydrogen)
Step 4 — Add the contributions
Why add? The molar mass of the whole compound is simply the total mass of every atom in the formula. Add each element's contribution:
72.066 + 14.112 = 86.178 g/mol
Step 5 — Final answer
Molar mass of Hexane = 86.178 g/mol
That means one mole of Hexane (C₆H₁₄) has a mass of about 86.18 grams.
Quick summary
Read the formula → count atoms → look up atomic masses → multiply → add → report g/mol. For C₆H₁₄, the total is 86.178 g/mol.
Common beginner mistakes
- Assuming all C₆H₁₄ isomers have identical boiling points and physical properties — branching significantly changes these values despite the shared formula.
- Confusing hexane (C₆H₁₄, alkane) with hexene (C₆H₁₂, alkene) or hexyne (C₆H₁₀, alkyne) — different degrees of saturation and reactivity.
- Underestimating hexane's flammability and neurotoxicity because it seems like a 'simple, inert' solvent.
Memory trick
Use the general alkane formula CₙH₂ₙ₊₂ as a quick check for saturation when identifying hexane or its isomers.
Mini practice
Without looking above, list the atoms in C₆H₁₄ and write one multiplication line for the heaviest element. Then check your work against Step 3.
Real-world example
If a recipe asks for 0.100 mol of Hexane, mass needed = 0.100 × 86.178 = 8.618 g. That is how chemists turn a mole amount into a weighable sample.
Atomic contribution table
Each row shows how much mass one element contributes to the total for C₆H₁₄.
| Element | Atoms | Atomic mass | Contribution | Mass % |
|---|---|---|---|---|
| C | 6 | 12.011 | 72.066 g/mol | 83.6% |
| H | 14 | 1.008 | 14.112 g/mol | 16.4% |
| Total molar mass | 86.178 g/mol | 100% | ||
Mass contribution chart
Count every atom in this formula, multiply by atomic mass, then add. That total is the molar mass used in lab weighing.
Download study sheets
Save a printable summary, revision sheet, practice worksheet, or laboratory reference for Hexane (C₆H₁₄).
Practice this calculation
Without looking above, write the atom count for C₆H₁₄, then compute the molar mass. Check your answer against 86.178 g/mol.
Next challenge: how many grams are in 0.250 mol of Hexane? Multiply 0.250 × 86.178 to get 21.544 g.
Physical and chemical properties
Physical properties
| Appearance | Colorless liquid |
| Color | Colorless |
| Odor | Mild gasoline-like odor |
| State (STP) | Liquid |
| Density | 0.655 g/cm³ (20 °C) |
| Melting point | −95 °C |
| Boiling point | 69 °C |
| Solubility | Practically insoluble in water (~13 mg/L); miscible with most nonpolar organic solvents |
| Crystal structure | Not applicable (liquid at room temperature) |
Chemical properties
| Classification | Saturated aliphatic hydrocarbon (alkane) |
| Family | Alkanes (straight-chain, C6) |
| Polarity | Nonpolar |
| Geometry | Tetrahedral at each carbon (sp³ hybridized, zigzag chain conformation) |
| Oxidation states | Not typically described by oxidation states (organic covalent compound) |
Applications
Industrial uses
- Vegetable oil extraction solvent (soybean, canola, and other oilseed processing)
- Degreasing and cleaning solvent in manufacturing
- Solvent component in adhesives, printing inks, and coatings
- Petroleum refining feedstock and gasoline blending component (with isomers)
Laboratory uses
- Nonpolar extraction and chromatography mobile phase solvent
- Reference compound for alkane combustion and halogenation reactions
- Model compound for teaching structural isomerism
Volatile organic compound (VOC) contributing to ground-level ozone formation; requires vapor recovery and emission controls in large-scale industrial solvent extraction operations.
No nutritional or biological role; n-hexane is specifically neurotoxic on chronic inhalation exposure, causing peripheral nerve damage via its 2,5-hexanedione metabolite.
Preparation and production
Obtained industrially by fractional distillation of the naphtha fraction of crude petroleum, followed by further separation to isolate n-hexane from its branched isomers and cycloalkane contaminants. Laboratory quantities are typically purchased as high-purity solvent-grade material rather than synthesized directly.
Global production is tied closely to petroleum refining output, with hexane recovered as a naphtha distillation cut; large volumes are specifically refined to food-grade purity for use as an oilseed extraction solvent.
Important reactions of Hexane
2 C₆H₁₄(l) + 19 O₂(g) → 12 CO₂(g) + 14 H₂O(g)
- Reaction type
- Complete combustion
- Conditions
- Ignition, excess oxygen
- Explanation
- Hexane burns completely in excess oxygen to form carbon dioxide and water, releasing substantial heat — the basis of its flammability hazard and fuel-related applications.
- Products
- Carbon dioxide and water vapor
- Why it matters
- Combustion energy release, fire hazard analysis
Related ideas: Combustion reactions · Stoichiometry · Thermochemistry
C₆H₁₄ + Cl₂ → C₆H₁₃Cl + HCl (UV light)
- Reaction type
- Free-radical halogenation
- Conditions
- UV light or heat initiation
- Explanation
- Chlorine substitutes for a hydrogen atom via a free-radical chain mechanism, producing a mixture of monochlorinated hexane isomers depending on which hydrogen is abstracted.
- Products
- Chlorohexane isomers and hydrogen chloride
- Why it matters
- Teaching free-radical substitution mechanisms
Related ideas: Free-radical mechanisms · Substitution reactions · Photochemistry
C₆H₁₄ → C₃H₆ + C₃H₈ (example cracking products)
- Reaction type
- Thermal cracking
- Conditions
- High temperature, industrial refinery conditions
- Explanation
- At high temperature without sufficient oxygen, hexane's C–C bonds can break homolytically, producing smaller alkane and alkene fragments — a process used industrially to convert heavier hydrocarbons into more valuable lighter ones.
- Products
- Smaller alkane and alkene fragments (product mix varies by conditions)
- Why it matters
- Petroleum refining, olefin production
Related ideas: Thermal cracking · Bond dissociation · Industrial petrochemistry
n-Hexane ⇌ 2-Methylpentane ⇌ 2,2-Dimethylbutane (isomerization, catalytic)
- Reaction type
- Catalytic isomerization
- Conditions
- Acidic catalyst (e.g., Pt/Al₂O₃ with HCl promoter), industrial reforming
- Explanation
- Straight-chain hexane can be catalytically rearranged into its more highly branched isomers, which have higher octane ratings valuable for gasoline blending.
- Products
- Branched hexane isomers
- Why it matters
- Gasoline octane improvement, petroleum refining
Related ideas: Isomerization · Catalysis · Fuel chemistry
History and discovery
Hexane, like other simple alkanes, became industrially significant with the growth of petroleum refining in the late 19th and 20th centuries. Its adoption as an oilseed extraction solvent expanded through the 20th century as it displaced older, less efficient mechanical pressing and other solvent extraction methods, becoming the dominant technology for vegetable oil production by the mid-20th century.
Isolated and characterized as petroleum refining and organic chemistry techniques matured through the 19th and early 20th centuries; no single discoverer is credited given its natural occurrence in crude oil.
Interesting facts
- Hexane's molecular formula, C₆H₁₄, corresponds to five different possible structural arrangements, all with identical molar mass.
- Most commercially extracted vegetable oil, including much of the world's soybean oil, passes through a hexane extraction step at some point in processing.
- n-Hexane's neurotoxicity was linked to documented outbreaks of peripheral neuropathy among workers in shoe manufacturing and other industries using hexane-based glues.
- Hexane's low boiling point (69 °C) makes it easy to recover and recycle after extraction, a major reason for its continued industrial popularity despite its flammability and toxicity concerns.
Comparison with similar compounds
Hexane (C₆H₁₄, 86.18 g/mol) and cyclohexane (C₆H₁₂, 84.16 g/mol) share nearly identical carbon counts but differ in ring formation, giving cyclohexane a lower hydrogen count and distinctly different physical properties despite their close molar masses.
Storage, handling, and safety
Store in tightly sealed, flame-resistant containers away from heat, sparks, and open flame. Use with adequate ventilation given its high volatility and flammability; store separately from strong oxidizers.
Highly flammable; use only in well-ventilated areas or fume hoods, away from ignition sources. Avoid prolonged inhalation exposure given its neurotoxic potential, and use appropriate gloves to minimize skin contact and defatting.
Highly flammable liquid; chronic inhalation exposure poses a specific peripheral neurotoxicity risk. Acute exposure can cause dizziness and central nervous system depression.
- Highly flammable liquid and vapor
- Chronic inhalation causes peripheral neuropathy (n-hexane specifically)
- Acute inhalation causes dizziness, headache, and CNS depression
- Skin defatting and irritation from repeated contact
Classification: GHS: Flam. Liq. 2, Skin Irrit. 2, Repr. 2, STOT RE 2 (repeated exposure)
Exam notes and student tips
Exam notes
- Molar mass C₆H₁₄ = 6(12.01) + 14(1.008) = 86.18 g/mol.
- General alkane formula CₙH₂ₙ₊₂ confirms hexane (n=6) is fully saturated with no rings or double bonds.
- Five structural isomers exist for C₆H₁₄, differing in carbon chain branching.
- Combustion: 2 C₆H₁₄ + 19 O₂ → 12 CO₂ + 14 H₂O (complete combustion, balanced with O₂ coefficient 19/2 per hexane doubled to whole numbers).
Student tips
- Use the general alkane formula CₙH₂ₙ₊₂ as a quick check for saturation when identifying hexane or its isomers.
- Draw out all five C₆H₁₄ isomers as practice for mastering structural isomerism concepts.
- Remember hexane's two main reactions — combustion and radical halogenation — as the primary reactivity to expect from any simple alkane.
Common mistakes
- Assuming all C₆H₁₄ isomers have identical boiling points and physical properties — branching significantly changes these values despite the shared formula.
- Confusing hexane (C₆H₁₄, alkane) with hexene (C₆H₁₂, alkene) or hexyne (C₆H₁₀, alkyne) — different degrees of saturation and reactivity.
- Underestimating hexane's flammability and neurotoxicity because it seems like a 'simple, inert' solvent.
Misconceptions
- Hexane is not chemically 'safe' simply because it doesn't react with common acids or bases — its flammability and neurotoxicity are separate, serious hazards.
- Commercial 'hexanes' solvent is not pure n-hexane — it is typically a mixture of several C₆H₁₄ isomers and related cycloalkanes.
- Vegetable oils processed with hexane extraction do not retain significant hexane residue — recovery and distillation steps remove the vast majority of solvent before the oil reaches consumers.
Practice questions
1. Calculate the molar mass of hexane (C₆H₁₄).
Show answer
6(12.01) + 14(1.008) = 86.18 g/mol
2. How many moles of CO₂ form from the complete combustion of 43.09 g of hexane?
Show answer
43.09 g ÷ 86.18 g/mol = 0.500 mol C₆H₁₄ → 0.500 × 6 = 3.00 mol CO₂
3. How many structural isomers exist for the molecular formula C₆H₁₄?
Show answer
Five: n-hexane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane.
4. Why is n-hexane specifically associated with peripheral neuropathy in occupational health studies?
Show answer
It is metabolized in the body to 2,5-hexanedione, a neurotoxic compound that damages peripheral nerve axons upon chronic inhalation exposure.
Frequently asked questions about Hexane
86.18 g/mol.
Chemistry of Hexane
The sections above give the number you need for calculations. Here we look more closely at how Hexane (C₆H₁₄) behaves chemically—so the molar mass connects to real reactions, properties, and laboratory practice.
Hexane (C₆H₁₄) is a straight-chain alkane with molar mass 86.18 g/mol (C 6 × 12.01 + H 14 × 1.008), a colorless, highly volatile, and flammable liquid that is completely nonpolar and virtually insoluble in water. As a saturated hydrocarbon containing only single C–C and C–H bonds, hexane is chemically unreactive under ordinary conditions apart from combustion and radical halogenation, making it an exceptionally useful inert solvent wherever a nonpolar extraction or reaction medium is needed.
The molecular formula C₆H₁₄ corresponds to five distinct structural isomers — n-hexane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane — all sharing the same formula and molar mass but differing in branching pattern, boiling point, and octane rating, making hexane a textbook case study in structural isomerism. Commercial "hexanes" solvent grade is often a mixture dominated by n-hexane along with some of these branched isomers and cyclopentane/methylcyclopentane, refined from petroleum through fractional distillation.
Hexane's defining industrial application is as the extraction solvent of choice for vegetable oil production: soybeans, canola, and other oilseeds are treated with hexane to dissolve and extract the oil far more efficiently than mechanical pressing alone, after which the hexane is recovered by distillation and recycled, leaving behind crude vegetable oil and defatted meal. This same solvent power, combined with hexane's low boiling point and easy recoverability, extends to its use as a general degreasing and cleaning solvent, a component of some adhesives and printing inks, and a carrier solvent in various industrial coating formulations — though its neurotoxic hazard on chronic inhalation exposure, particularly to peripheral nerves, requires careful ventilation controls wherever it is used at scale.
C₆H₁₄ satisfies the general alkane formula CₙH₂ₙ₊₂ for n = 6, confirming it is a fully saturated hydrocarbon with no rings or multiple bonds. The straight-chain arrangement (n-hexane) is only one of five possible structural isomers sharing this formula; branched isomers rearrange the same six carbons and fourteen hydrogens into different connectivity patterns.
Hexane is chemically inert under normal conditions, undergoing essentially only two significant reaction types: combustion with oxygen (releasing substantial heat, used implicitly whenever hexane vapor ignites) and radical halogenation under UV light or heat, where halogen atoms substitute for hydrogen atoms via a free-radical chain mechanism. It does not react with common acids, bases, or oxidizing agents under mild conditions, which is precisely why it makes such a reliable, unreactive extraction and cleaning solvent.
The five structural isomers of C₆H₁₄
Hexane's molecular formula corresponds to five distinct constitutional isomers: n-hexane (straight chain), 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane. All five share the identical molar mass of 86.18 g/mol, yet each has a different boiling point, branching pattern, and combustion behavior, making C₆H₁₄ a classic teaching example for illustrating how molecular formula alone does not determine a compound's physical or chemical properties.
Vegetable oil extraction solvent
Hexane is the dominant solvent used industrially to extract oil from soybeans, canola seed, and other oilseeds, dissolving the oil far more thoroughly than mechanical pressing alone. After extraction, the hexane is recovered by distillation and recycled, leaving crude vegetable oil and hexane-free defatted meal (used in animal feed) — a process responsible for the majority of the world's vegetable oil supply.
n-Hexane neurotoxicity and occupational exposure limits
Chronic inhalation of n-hexane vapor is specifically neurotoxic, causing peripheral neuropathy through its metabolite 2,5-hexanedione, which damages axons in peripheral nerves. This distinct toxicological profile — worse for n-hexane than for many of its branched isomers — has led to strict occupational exposure limits in industries using hexane-based solvents, particularly in shoe manufacturing, furniture upholstery, and printing where historical outbreaks of hexane-related neuropathy were documented.
Fractional distillation and petroleum refining source
Hexane is obtained from crude oil through fractional distillation of the naphtha fraction, alongside its structural isomers and related C₆ hydrocarbons like cyclohexane and methylcyclopentane. Its position in the naphtha boiling range also makes it and its isomers important contributors to gasoline's octane characteristics, since branched isomers like 2,3-dimethylbutane resist engine knock far better than straight-chain n-hexane.
Free-radical halogenation chain mechanism
Hexane undergoes halogenation (e.g., with chlorine or bromine) only via a free-radical chain mechanism requiring UV light or heat to initiate, proceeding through initiation (halogen radical formation), propagation (hydrogen abstraction and radical substitution), and termination steps — a foundational mechanism taught throughout introductory organic chemistry using simple alkanes like hexane as the model substrate.
Recalculate any formula with the molar mass calculator, compare atoms on the periodic table, or browse more compounds in the hydrocarbon library.
References and further reading
- PubChem CID 8058: Hexane compound data
- NIOSH: Occupational exposure limits and neurotoxicity data for n-hexane
- NIST Chemistry WebBook: Thermodynamic properties