Undecane

Structural formula
General
Surname	Undecane
other names	n -Undecane Undecan n -undecan Hendekan
Molecular formula	C 11 H 24
Brief description	colorless liquid
External identifiers / databases
CAS number 1120-21-4 EC number 214-300-6 ECHA InfoCard 100.013.001 PubChem 14257 Wikidata Q150731
properties
Molar mass	156.31 g mol −1
Physical state	liquid
density	0.74 g cm −3 (20 ° C)
Melting point	−26 ° C
boiling point	196 ° C
Vapor pressure	0.55 hPa (25 ° C) 2.27 hPa (40 ° C) 4.05 hPa (50 ° C)
solubility	practically insoluble in water (20 ° C)
Refractive index	1.4164 (20 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 304 EUH: 066 P: 301 + 310-331
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Undecane (also n -undecane ) is a colorless liquid with the empirical formula C ₁₁ H ₂₄ or CH ₃ (CH ₂ ) ₉ CH ₃ , which is one of the unbranched alkanes of hydrocarbons in organic chemistry .

The substance group of the undecanes comprises a total of 159 further, branched constitutional isomers.

properties

Physical Properties

Undecane is a colorless liquid that boils at 196 ° C under normal pressure . According to Antoine, the vapor pressure function results from log ₁₀ (P) = A− (B / (T + C)) (P in bar, T in K) with A = 4.10164, B = 1572.477 and C = −85.128 in the temperature range from 377.6 to 470.2 K. Two polymorphic crystal forms occur in the solid phase . Polymorph II converts to polymorph I at −36.5 ° C with a heat of transformation of 6.858 kJ mol ⁻¹ . Polymorph I melts at −25.6 ° C with a heat of fusion of 22.18 kJ mol ⁻¹ .

Compilation of the most important thermodynamic properties

property	Type	Value [unit]	Remarks
Standard enthalpy of formation	Δ f H 0 liquid Δ f H 0 gas	−327.2 kJ mol −1 −270.3 kJ mol −1
Enthalpy of combustion	Δ c H 0 liquid	−7431.3 kJ mol −1
Heat capacity	c p	345.05 J mol −1 K −1 (25 ° C) 2.21 J g −1 K −1 (25 ° C)	as a liquid
Critical temperature	T c	639 K
Critical pressure	p c	19.5 bar
Critical volume	V c	0.695 l mol −1
Critical density	ρ c	0.2372 g ml −1
Acentric factor	ω c	0.530
Enthalpy of evaporation	Δ V H 0	56.434 kJ mol −1

Safety-related parameters

The compound is considered a flammable liquid. Flammable vapor-air mixtures can form above the flash point. The compound has a flash point of 61 ° C. The explosion range is between 0.6% by volume (42 g / m ³ ) as the lower explosion limit (LEL) and 6.5% by volume (425 g / m ³ ) as the upper explosion limit (UEL). The limit gap width was determined to be 0.83 mm. This results in an assignment to explosion group IIA. The ignition temperature is 195 ° C. The substance therefore falls into temperature class T4.

use

Undecane is a component of gasoline and diesel fuel , among other things .

hazards

Undecane degreases and reddens the skin . The liquid causes pain and redness in the eyes .

Web links

Commons : Undecan  - collection of images, videos and audio files

Wiktionary: Undecan  - explanations of meanings, word origins, synonyms, translations

Individual evidence

1. ↑ ^{a b c d e f g h i j k l m} Entry on Undecane in the GESTIS substance database of the IFA , accessed on April 16, 2018(JavaScript required) .
2. ↑ Data sheet n-Undecane (PDF) from Merck , accessed on January 21, 2018.
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-516.
4. ↑ Cooper, AR; Crowne, CWP; Farrell, PG: Gas-Liquid Chromatographic Studies of Electron-donor-acceptor system. Part 2. — Interactions of aromatic hydrocarbons and heterocycles with 2,4,7-trinitrofluorenones in Trans. Faraday Soc. 63 (1967) 447-454, doi : 10.1039 / TF9676300447 .
5. ↑ Camin, David L .; Rossini, Frederick D .: Physical Properties of Fourteen API Research Hydrocarbons, C 9 to C 15 in J. Phys. Chem. 59 (1955) 1173-1179, doi : 10.1021 / j150533a014 .
6. ↑ ^{a b c d} Finke, HL; Gross, ME; Waddington, G .; Huffman, HM: Low-temperature thermal data for the nine normal paraffin hydrocarbons from octane to hexadecane in J. Am. Chem. Soc. 76 (1954) 333-341.
7. ↑ ^{a b c} Prosen, EJ; Rossini, FD: Heats of combustion and formation of the paraffin hydrocarbons at 25 ° C in J. Res. NBS, 1945, 263-267.
8. ^ ^{A b c d e} Carl L. Yaws, Prasad K. Narasimhan: Thermophysical Properties of Chemicals and Hydrocarbons - Chapter 1: Critical Properties and Acentric Factor, Organic Compounds. 1st edition. Elsevier, 2008, ISBN 978-0-8155-1596-8 , p. 65, doi: 10.1016 / B978-081551596-8.50006-7 .
9. ↑ Wadsö, I., A heat of vaporization calorimeter for work at 25 ° C and for small amounts of substances, Acta Chem. Scand., 1966, 20, 536.
10. ↑ ^{a b c d e} E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.