Tungsten

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Other names/abbreviations:

W Wolfram

Element no:	74
Element group:	6 (IUPAC) VI B (American labelling) VI A (European labelling)
Element type:	Transition metals
CAS-Number:	7440-33-7
EINECS-Number:	231-143-9

Quantitative analysis

Method - Inductively Coupled Plasma Method [5]. A portion of the sample is digested in a combination of acids. The digest is aspirated into an 8,000 K argon plasma where resulting light emission is quantified for 30 elements simultaneously.

Method limit of detection in water = 0.03 mg/L
Method limit of detection in soil = 2.00 mg/kg

Safety

Symbol: -
R-phrases: -
S-phrases: -

Physical properties

Appearance
	Physical state @ 20°C:	Solid [3]
	Color:	Gray [3]
	Odor:	Odourless [3]

Bulk properties
	Molecular weight (g/mol):	183.84(1) [1]
	Melting point (°C):	3422 [1]
	Boiling point (°C):	5500 [1]
	Density (g/cm3):	19.3 [1]
	Molar volume (cm3):	9.53 (20°C) [2]
	Elastic properties: Young's modulus (GPa): Rigidity modulus (GPa): Bulk modulus (GPa): Poissons ratio:	415.3 [2] 151-158 [2] 349 [2] 0.28-031 [2]

Thermodynamic properties
	ΔfH°gas (kJ/mol):	849.4 [4]
	ΔfH°solid (kJ/mol):	0.0 [4]
	ΔH°fusion (kJ/mol):	52.31 [4]
	ΔH°vaporization (kJ/mol):	824±21 [1]
	S°gas (J/K·mol):	174.0 [4]
	S°solid (J/K·mol):	32.6 [4]
	ΔfG°gas (kJ/mol):	807.1 [4]
	Cp (gas) (J/K·mol):	21.3 (25 °C) [4]
	Cp (solid) (J/K·mol):	26.1617 (20 °C) [2] 24.27 (25 °C) [4] 25.2384 (100 °C) [2] 26.008 (500 °C) [2]
	Coeff. of linear thermal expansion (106 K-1):	4.5 (20 °C) [2] 4.5 (25 °C) [4] 4.6 (100 °C) [2] 4.6 (500 °C) [2] 4.6 (1000 °C) [2] 5.4 (2000 °C) [2] 6.6 (3000 °C) [2]

Crystal structure
	Crystal type:	Body centered cubic [2]

Electronic properties
	Electron configuration:	1s2-2s2-2p6-3s2-3p6-3d10-4s2-4p6-4d10-4f14-5s2-5p6-5d4-6s2
	Ionic radius (Å):	W(VI): 0.60 (6-coordinate) [1] W(V): 0.62 (6-coordinate) [1] W(IV): 0.66 (6-coordinate) [1]

Conductivity
	Electrical resisitvity (μΩ·cm):	5.4 (20 °C) [2] 5.2 (25 °C) [2] 7.3 (100 °C) [2] 18.0 (500 °C) [2] 33.0 (1000 °C) [2] 65.0 (2000 °C) [2] 100.0 (3000 °C) [2]
	Thermal (W/m·K):	167 (20 °C) [2] 174 (27 °C) [4] 159 (100 °C) [2] 121 (500 °C) [2] 111 (1000 °C) [2] 93 (2000 °C) [2]

References

1: Greenwood,N.N., Earnshaw,A. Chemistry of the elements
2nd edition (1997) Edited by Greenwood,N.N., Earnshaw,A. pp. 1-1340, Butterworth-Heinemann. Oxford. Great Britain

2: Buch,A. Pure Metals Properties. A Scientific-Technical Handbook
1st edition (1999) Edited by Buch,A. pp. 1-306, ASM International and Freund Publishing House Ltd. Ohio. USA

3: Merck. ChemDAT The Merck Chemical Database Ver. 1.1.5

4: CRC Handbook of Chemistry and Physics
75th edition (1994) Edited by Lide,D.R. , CRC Press Inc. Boca Raton, USA

5: Standard Methods for the Analysis of Water and Wastewater, APHA, 1992, 18th edition

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© Michael Pilgaard
Created: October 7, 2008
Last update: October 9, 2008