Undecane

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| verifiedrevid = 470619567

| ImageFile = Undecane-2D-Skeletal.svg

| ImageFile_Ref = {{chemboximage|correct|??}}

| ImageSize = 255

| ImageClass = skin-invert

| ImageAlt = Structural formula of undecane

| ImageFile1 = UndecaneFull.png

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| ImageSize1 = 255

| ImageClass1 = skin-invert

| ImageAlt1 = Skeletal formula of undecane with all implicit carbons shown, and all explicit hydrogens added

| ImageFile2 = Undecane 3D ball.png

| ImageFile2_Ref = {{chemboximage|correct|??}}

| ImageSize2 = 255

| ImageAlt2 = Ball-and-stick model of the undecane molecule

| PIN = Undecane{{Cite web|title=undecane - Compound Summary|url=https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=14257&loc=ec_rcs|work=PubChem Compound|publisher=National Center for Biotechnology Information|access-date=5 January 2012|location=USA|date=16 September 2004|at=Identification and Related Records}}

|Section1={{Chembox Identifiers

| CASNo = 1120-21-4

| CASNo_Ref = {{cascite|correct|CAS}}

| PubChem = 14257

| ChemSpiderID = 13619

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| UNII = JV0QT00NUE

| UNII_Ref = {{fdacite|correct|FDA}}

| EINECS = 214-300-6

| UNNumber = 2330

| MeSHName = undecane

| ChEBI = 46342

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 132474

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| RTECS = YQ1525000

| Beilstein = 1697099

| SMILES = CCCCCCCCCCC

| StdInChI = 1S/C11H24/c1-3-5-7-9-11-10-8-6-4-2/h3-11H2,1-2H3

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = RSJKGSCJYJTIGS-UHFFFAOYSA-N

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

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|Section2={{Chembox Properties

| C=11 | H=24

| Appearance = Colorless liquid

| Odor = Gasoline-like to Odorless

| Density = 740 g/L

| MeltingPtC = -26

| BoilingPtC = 196

| LogP = 6.312

| VaporPressure = 55 Pa (at 25 °C){{cite book |last1=Yaws |first1=Carl L.|title= Chemical Properties Handbook|year= 1999|publisher= McGraw-Hill|location= New York|isbn= 0-07-073401-1|pages= 159–179}}

| HenryConstant = 5.4 nmol Pa⁻¹ kg⁻¹

| RefractIndex = 1.417

| MagSus = −131.84·10⁻⁶ cm³/mol

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|Section3={{Chembox Thermochemistry

| DeltaHf = −329.8 – −324.6 kJ mol⁻¹

| DeltaHc = −7.4339 – −7.4287 MJ mol⁻¹

| Entropy = 458.15 J K⁻¹ mol⁻¹

| HeatCapacity = 345.05 J K⁻¹ mol⁻¹

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|Section4={{Chembox Hazards

| GHSPictograms = {{GHS flame}} {{GHS health hazard}}

| GHSSignalWord = DANGER

| HPhrases = {{H-phrases|304|315|319|331|335}}

| PPhrases = {{P-phrases|261|301+310|305+351+338|311|331}}

| FlashPtC = 60.0

| NFPA-H = 3

| NFPA-F = 2

| NFPA-I = 0

| AutoignitionPtC = 240

| LD50 = > 2000 mg/kg (rat, oral)
> 5000 mg/kg (rat, dermal)

| LC50 = > 20 mg/L (rat, 8 hours)

| ExternalSDS = [https://www.fishersci.com/msdsproxy%3FproductName%3DAC140660100%26productDescription%3DN-UNDECANE%252C%2B99%2525%2B10LT%26catNo%3DAC140660100%26vendorId%3DVN00032119%26storeId%3D10652 Fisher Scientific]

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|Section5={{Chembox Related

| OtherFunction_label = alkanes

| OtherFunction = {{Unbulleted list|Decane|Dodecane}}

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Undecane (also known as hendecane) is a liquid alkane hydrocarbon with the chemical formula CH₃(CH₂)₉CH₃. It is used as a mild sex attractant for various types of moths and cockroaches, and an alert signal for a variety of ants.{{cite book | author = Hölldobler B, Wilson EO | date = 1990 | title = The Ants | publisher = Harvard University Press | isbn = 0-674-04075-9 | page = 287 }} It has 159 isomers.{{Cite journal | doi = 10.6084/M9.FIGSHARE.24309724| date = 2023| last1 = Stoermer| first1 = Martin| title = Undecane Isomers | journal = Figshare}}

Undecane may also be used as an internal standard in gas chromatography when working with other hydrocarbons. Since the boiling point of undecane (196 °C) is well known, it may be used as a comparison for retention times in a gas chromatograph for molecules whose structure has been freshly elucidated. For example, if one is working with a 50 m crosslinked methyl silicone capillary column with an oven temperature increasing slowly, beginning around 60 °C, an 11-carbon molecule like undecane may be used as an internal standard to be compared with the retention times of other 10-, 11-, or 12- carbon molecules, depending on their structures.