Heptane

Heptane
Brief description	Reference fuel (RON = 0 by definition)
properties
Physical state	liquid
calorific value	8.5 kWh / L = 12.5 kWh / kg
Octane number	0 RON (by definition)
Flash point	−7 ° C
Ignition temperature	220 ° C
Explosive limit	0.84-6.7% by volume
Temperature class	T3
Explosion class	IIA
safety instructions
UN number	1206
Hazard number	33
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Structural formula
General
Surname	Heptane
other names	n -heptane
Molecular formula	C 7 H 16
Brief description	colorless liquid with a faint gasoline odor
External identifiers / databases
EC number	205-563-8
ECHA InfoCard	100.005.058
PubChem	8900
Wikidata	Q310957
properties
Molar mass	100.21 g mol −1
Physical state	liquid
density	0.68 g cm −3
Melting point	−91 ° C
boiling point	98 ° C
Vapor pressure	47.4 h Pa (20 ° C)
solubility	very heavy in water (2.2 mg l −1 at 25 ° C); soluble in many organic solvents such as ethanol , white spirit , benzene or tetrachloromethane ;
Refractive index	1.3878
safety instructions
H and P phrases	H: 225-304-315-336-410
	P: 210-240-273-301 + 330 + 331-302 + 352-403 + 233
MAK	500 ml m −3 , 2100 mg m −3
	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

Heptane is a chain-like hydrocarbon from the substance group of alkanes having the empirical formula C ₇ H ₁₆ . He is the unbranched representatives of nine heptane - isomers . Heptane is flammable and hazardous to water ( WGK 2).

Occurrence and extraction

Heptane occurs naturally in crude oil from which it is obtained by distillation . It is also found in the essential oils of some pines and in the fruits of Pittosporum resiniferum (so-called petroleum nuts ) that are common in the Philippines .

properties

Physical Properties

Heptane is a clear, low-viscosity liquid that boils at 98 ° C at normal pressure. The vapor pressure function results according to Antoine according to log ₁₀ (P) = A− (B / (T + C)) (P in bar, T in K) with A = 4.81803, B = 1635.409 and C = −27.338 in the temperature range from 185.3 to 295.6 K and with A = 4.02832, B = 1268.636 and C = −56.199 in the temperature range from 299.1 to 372.4 K. The temperature dependence of the enthalpy of vaporization can be determined according to the equation Δ _V H ⁰ = Aexp (−βT _r ) (1 − T _r ) ^β (Δ _V H ⁰ in kJ / mol, T _r = (T / T _c ) reduced temperature) with A = 53.66 kJ / mol, Describe β = 0.2831 and T _c = 540.2 K in the temperature range between 298 K and 363 K. With 2.2 mg · l ⁻¹ at 25 ° C , heptane is only very slightly soluble in water. The calorific value is 44.7 MJ / kg.

Heptane vapor pressure function
Temperature dependence of the heat of vaporization of heptane

The compound forms azeotropically boiling mixtures with a number of other solvents . The azeotropic compositions and boiling points can be found in the following table. No azeotropes are formed with cyclohexane , hexane , toluene , ethylbenzene , xylene , cyclohexanol, and carbon disulfide .

Azeotropes with various solvents
solvent		water	Methanol	Ethanol	1-propanol	2-propanol
Content of heptane	in%	87	59	51	64	50
boiling point	in ° C	79	49	71	88	76
solvent		Ethylene glycol methyl ether	Ethylene glycol ethyl ether	acetone	Methyl ethyl ketone	Methyl isobutyl ketone
Content of heptane	in%	77	86	10	30th	87
boiling point	in ° C	92	97	56	77	98
solvent		1-butanol	i -butanol	2-butanol	Ethanediol	Acetonitrile
Content of heptane	in%	82	73	62	97	54
boiling point	in ° C	94	91	89	98	69
solvent		Dioxane	Methyl acetate	Ethyl acetate	Isopropyl acetate	DMF
Content of heptane	in%	56	3	6th	33	95
boiling point	in ° C	92	57	77	88	97

Safety-related parameters

Heptane forms highly flammable vapor-air mixtures. The compound has a flash point of −7 ° C. The explosion range is between 0.84% by volume (35 g / m³) as the lower explosion limit (LEL) and 6.7% by volume (280 g / m³) as the upper explosion limit (UEL). A correlation of the explosion limits with the vapor pressure function results in a lower explosion point of −8 ° C and an upper explosion point of 27 ° C. The maximum explosion pressure is 9.4 bar. The limit gap width was determined to be 0.91 mm. This results in an assignment to explosion group IIA. With a minimum ignition energy of 0.24 mJ, vapor-air mixtures are extremely ignitable. The ignition temperature is 220 ° C. The substance therefore falls into temperature class T3. The electrical conductivity is very low at 7.0 · 10 ⁻¹⁴ S · m ⁻¹ .

According to the dangerous goods regulations , heptane is assigned to class 3 (flammable liquids) with packing group II (medium hazard) and UN number 1206 (label: 3).

use

Heptane is used as a non-polar solvent in organic synthesis. Since the compound is very easy on knocking, it is used with the octane number "RON = 0" as one of the two comparison fuels in addition to the knock- proof isooctane ("RON = 100") for determining the octane number .

n-Heptane is the main component of some start-up sprays .

1-Bromoheptane can be obtained by brominating n-heptane .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s entry on heptane in the GESTIS substance database of the IFA , accessed on July 26, 2019(JavaScript required) .
↑ ^a ^b entry on heptane. In: Römpp Online . Georg Thieme Verlag, accessed on December 28, 2014.
^ CRC Handbook of Chemistry and Physics , 57. Edition, CRC Press, Boca Raton, Florida, 1976, Section C, Physical Constants of Organic Compounds , pp. C-328.
↑ Entry on Heptane in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ ^a ^b ^c ^d ^e ^f ^g ^h E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
↑ K. Griesbaum, A. Behr, D. Biedenkapp, H.-W. Voges, D. Garbe, C. Paetz, G. Collin, D. Mayer, H. Höke: Hydrocarbons in Ullmann's Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH Verlag GmbH & Co, Weinheim, doi : 10.1002 / 14356007.a13_227 .
↑ Carruth, GF; Kobayashi, R .: Vapor Pressure of Normal Paraffins Ethane Through n -Decane from Their Triple Points to About 10 Mm Hg in J. Chem. Eng. Data 18 (1973) 115-126, doi: 10.1021 / je60057a009 .
↑ Williamham, CB; Taylor, WJ; Pignocco, JM; Rossini, FD: Vapor Pressures and Boiling Points of Some Paraffin, Alkylcyclopentane, Alkylcyclohexane, and Alkylbenzene Hydrocarbons in J. Res. Natl. Bur. Stand. (US) 35 (1945) 219-244.
↑ Majer, V .; Svoboda, V .: Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation , Blackwell Scientific Publications, Oxford, 1985, 300.
↑ ^a ^b I.M. Smallwood: Handbook of organic solvent properties , Arnold London 1996, ISBN 0-340-64578-4 , pp. 12-13.
↑ Technical rule for operational safety - TRBS 2153, BG RCI leaflet T033 Avoidance of ignition hazards due to electrostatic charges , as of April 2009, Jedermann-Verlag Heidelberg.
^ H. Altenburg, I. Bang, K. Bartelt, Fr. Baum, C. Brahm, W. Cramer, K. Dieterich, R. Ditmar, M. Dohrn, H. Einbeck, H. Euler, ES Faust, C. Funk, O. v. Fürth, O. Gerngroß: Biochemisches Handlexikon 1st volume, 1st half carbon, hydrocarbons, alcohols of the aliphatic series, phenols . Springer-Verlag, 2013, ISBN 978-3-642-90817-0 , pp. 101 ( limited preview in Google Book search).

Web links

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

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

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s entry on heptane in the GESTIS substance database of the IFA , accessed on July 26, 2019(JavaScript required) .

[roempp-2] try on heptane. In: Römpp Online . Georg Thieme Verlag, accessed on December 28, 2014.

[CRC-3] CRC Handbook of Chemistry and Physics , 57. Edition, CRC Press, Boca Raton, Florida, 1976, Section C, Physical Constants of Organic Compounds , pp. C-328.

[CLP_100.005.058-4] Entry on Heptane in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[Brandes-5] ↑ ^a ^b ^c ^d ^e ^f ^g ^h E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.

[6] K. Griesbaum, A. Behr, D. Biedenkapp, H.-W. Voges, D. Garbe, C. Paetz, G. Collin, D. Mayer, H. Höke: Hydrocarbons in Ullmann's Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH Verlag GmbH & Co, Weinheim, doi : 10.1002 / 14356007.a13_227 .

[7] Carruth, GF; Kobayashi, R .: Vapor Pressure of Normal Paraffins Ethane Through n -Decane from Their Triple Points to About 10 Mm Hg in J. Chem. Eng. Data 18 (1973) 115-126, doi: 10.1021 / je60057a009 .

[8] Williamham, CB; Taylor, WJ; Pignocco, JM; Rossini, FD: Vapor Pressures and Boiling Points of Some Paraffin, Alkylcyclopentane, Alkylcyclohexane, and Alkylbenzene Hydrocarbons in J. Res. Natl. Bur. Stand. (US) 35 (1945) 219-244.

[Majer_Svoboda-9] Majer, V .; Svoboda, V .: Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation , Blackwell Scientific Publications, Oxford, 1985, 300.

[Smallwood-10] I.M. Smallwood: Handbook of organic solvent properties , Arnold London 1996, ISBN 0-340-64578-4 , pp. 12-13.

[11] Technical rule for operational safety - TRBS 2153, BG RCI leaflet T033 Avoidance of ignition hazards due to electrostatic charges , as of April 2009, Jedermann-Verlag Heidelberg.

[H._Altenburg,_I._Bang,_K._Bartelt,_Fr._Baum,_C._Brahm,_W._Cramer,_K._Dieterich,_R._Ditmar,_M._Dohrn,_H._Einbeck,_H._Euler,_E.S._Faust,_C._Funk,_O._v._Fürth,_O._Gerngroß-12] H. Altenburg, I. Bang, K. Bartelt, Fr. Baum, C. Brahm, W. Cramer, K. Dieterich, R. Ditmar, M. Dohrn, H. Einbeck, H. Euler, ES Faust, C. Funk, O. v. Fürth, O. Gerngroß: Biochemisches Handlexikon 1st volume, 1st half carbon, hydrocarbons, alcohols of the aliphatic series, phenols . Springer-Verlag, 2013, ISBN 978-3-642-90817-0 , pp. 101 ( limited preview in Google Book search).