Difference between revisions of "Titanium"

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[[File:Titanium_shavings.jpg|thumb|300px|Titanium shavings.]]
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{{Infobox element
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'''Titanium''' is a transition metal with the symbol Ti and the atomic number 22. It is a grayish, light metal that has high corrosion resistance, but can be converted to multiple oxidation states, most commonly +4 and +3.
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|image name=File:Titanium_shavings.jpg
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|image size=
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|image name comment= Titanium shavings.
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|image name 2=
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|image alt 2=
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|image size 2=
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|image name 2 comment=
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<!-- General properties -->
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|name=Titanium
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|symbol=Ti
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|pronounce= /tɪˈteɪniəm/
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|pronounce ref=
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|pronounce comment=
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|pronounce 2=
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|alt name=
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|alt names=
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|allotropes=
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|appearance= Silvery white
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<!-- Periodic table -->
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|above=-
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|below=[[Zirconium|Zr]]
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|left=[[Scandium]]
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|right=[[Vanadium]]
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|number=22
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|atomic mass=47.87
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|atomic mass 2=
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|atomic mass ref=
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|atomic mass comment=
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|series=
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|series ref=
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|series comment=
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|series color=
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|group=
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|group ref=
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|group comment=4
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|period=4
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|period ref=
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|period comment=
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|block=d
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|block ref=
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|block comment=
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|electron configuration= [Ar] 3d<sup>2</sup> 4s<sup>2</sup>
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|electron configuration ref=
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|electron configuration comment=
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|electrons per shell=2, 8, 10, 2
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|electrons per shell ref=
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|electrons per shell comment=
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<!-- Physical properties -->
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|physical properties comment=
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|color=silvery,metalic
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|phase=solid
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|phase ref=
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|phase comment=
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|melting point K=1941
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|melting point C=1668
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|melting point F=​3034
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|melting point ref=
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|melting point comment=
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|boiling point K=3560
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|boiling point C=3287
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|boiling point F=5949
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|boiling point ref=
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|boiling point comment=
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|sublimation point K=
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|sublimation point C=
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|sublimation point F=
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|sublimation point ref=
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|sublimation point comment=
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|density gplstp=
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|density gplstp ref=
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|density gplstp comment=
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|density gpcm3nrt= 4.506
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|density gpcm3nrt ref=
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|density gpcm3nrt comment=
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|density gpcm3nrt 2=
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|density gpcm3nrt 2 ref=
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|density gpcm3nrt 2 comment=
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|density gpcm3nrt 3=
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|density gpcm3nrt 3 ref=
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|density gpcm3nrt 3 comment=
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|density gpcm3mp= 4.11
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|density gpcm3mp ref=
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|density gpcm3mp comment=
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|density gpcm3bp=
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|density gpcm3bp ref=
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|density gpcm3bp comment=
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|molar volume=
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|molar volume unit =
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|molar volume ref=
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|molar volume comment=
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|triple point K=
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|triple point kPa=
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|triple point ref=
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|triple point comment=
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|triple point K 2=
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|triple point kPa 2=
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|triple point 2 ref=
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|triple point 2 comment=
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|critical point K=
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|critical point MPa=
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|critical point ref=
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|critical point comment=
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|heat fusion=14.15
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|heat fusion ref=
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|heat fusion comment=
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|heat fusion 2=
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|heat fusion 2 ref=
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|heat fusion 2 comment=
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|heat vaporization=425
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|heat vaporization ref=
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|heat vaporization comment=
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|heat capacity=25.060
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|heat capacity ref=
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|heat capacity comment=
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|heat capacity 2=
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|heat capacity 2 ref=
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|heat capacity 2 comment=
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|vapor pressure 1=1982
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|vapor pressure 10=2171
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|vapor pressure 100=2403
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|vapor pressure 1 k=2692
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|vapor pressure 10 k=3064
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|vapor pressure 100 k=3558
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|vapor pressure ref=
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|vapor pressure comment=
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|vapor pressure 1 2=
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|vapor pressure 10 2=
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|vapor pressure 100 2=
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|vapor pressure 1 k 2=
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|vapor pressure 10 k 2=
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|vapor pressure 100 k 2=
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|vapor pressure 2 ref=
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|vapor pressure 2 comment=
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<!-- Atomic properties -->
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|atomic properties comment=
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|oxidation states=4, 3, 2, 1, −1, −2 ​(an amphoteric oxide)
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|oxidation states ref=
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|oxidation states comment=
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|electronegativity=1.54
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|electronegativity ref=
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|electronegativity comment=
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|ionization energy 1=658.8
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|ionization energy 1 ref=
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|ionization energy 1 comment=
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|ionization energy 2=1309.8
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|ionization energy 2 ref=
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|ionization energy 2 comment=
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|ionization energy 3=2652.5
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|ionization energy 3 ref=
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|ionization energy 3 comment=
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|number of ionization energies=
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|ionization energy ref=
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|ionization energy comment=
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|atomic radius=147
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|atomic radius ref=
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|atomic radius comment=
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|atomic radius calculated=
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|atomic radius calculated ref=
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|atomic radius calculated comment=
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|covalent radius=160±8
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|covalent radius ref=
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|covalent radius comment=
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|Van der Waals radius=
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|Van der Waals radius ref=
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|Van der Waals radius comment=
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<!-- Miscellanea -->
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|crystal structure= ​
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|crystal structure prefix=
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|crystal structure ref=
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|crystal structure comment=hexagonal close-packed (hcp)
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|crystal structure 2=
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|crystal structure 2 prefix=
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|crystal structure 2 ref=
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|crystal structure 2 comment=
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|speed of sound=
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|speed of sound ref=
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|speed of sound comment=
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|speed of sound rod at 20=
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|speed of sound rod at 20 ref=
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|speed of sound rod at 20 comment=
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|speed of sound rod at r.t.=5090
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|speed of sound rod at r.t. ref=
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|speed of sound rod at r.t. comment=
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|thermal expansion=
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|thermal expansion ref=
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|thermal expansion comment=
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|thermal expansion at 25=8.6
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|thermal expansion at 25 ref=
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|thermal expansion at 25 comment=
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|thermal conductivity=21.9
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|thermal conductivity ref=
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|thermal conductivity comment=
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|thermal conductivity 2=
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|thermal conductivity 2 ref=
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|thermal conductivity 2 comment=
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|thermal diffusivity=
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|thermal diffusivity ref=
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|thermal diffusivity comment=
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|electrical resistivity=
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|electrical resistivity unit prefix=
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|electrical resistivity ref=
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|electrical resistivity comment=
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|electrical resistivity at 0=
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|electrical resistivity at 0 ref=
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|electrical resistivity at 0 comment=
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|electrical resistivity at 20=420
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|electrical resistivity at 20 ref=
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|electrical resistivity at 20 comment=
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|band gap=
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|band gap ref=
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|band gap comment=
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|Curie point K=
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|Curie point ref=
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|Curie point comment=
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|magnetic ordering= Paramagnetic
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|magnetic ordering ref=
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|magnetic ordering comment=
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|tensile strength=
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|tensile strength ref=
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|tensile strength comment=
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|Young's modulus=116
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|Young's modulus ref=
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|Young's modulus comment=
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|Shear modulus=44
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|Shear modulus ref=
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|Shear modulus comment=
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|Bulk modulus=110
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|Bulk modulus ref=
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|Bulk modulus comment=
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|Poisson ratio=0.32
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|Poisson ratio ref=
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|Poisson ratio comment=
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|Mohs hardness=6.0
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|Mohs hardness ref=
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|Mohs hardness comment=
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|Mohs hardness 2=
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|Mohs hardness 2 ref=
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|Mohs hardness 2 comment=
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|Vickers hardness=830–3420
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|Vickers hardness ref=
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|Vickers hardness comment=
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|Brinell hardness=716–2770
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|Brinell hardness ref=
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|Brinell hardness comment=
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|CAS number=7440-32-6
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|CAS number ref=
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|CAS number comment=
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<!-- History -->
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|naming=
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|predicted by=
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|prediction date ref=
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|prediction date=
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|discovered by=William Gregor
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|discovery date ref=
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|discovery date=1791
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|first isolation by= Jöns Jakob Berzelius
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|first isolation date ref=
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|first isolation date=1825
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|discovery and first isolation by=
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|named by=Martin Heinrich Klaproth
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|named date ref=
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|named date=1795
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|history comment label=
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|history comment=
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<!-- Isotopes -->
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|isotopes=
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|isotopes comment=
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|engvar=
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}}
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'''Titanium''' is a transition metal with the symbol '''Ti''' and the atomic number 22. It is a grayish, light metal that has high corrosion resistance, but can be converted to multiple oxidation states, most commonly +4 and +3.
  
 
==Properties==
 
==Properties==
 
===Physical properties===
 
===Physical properties===
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Titanium is a gray metal of low density, only 60% more than that of [[aluminium]], but is twice as strong. It is a common refractory material, and prized for its mechanical properties. It is slightly [[paramagnetism|paramagnetic]] and exists in three [[Allotrope|allotropes]]. Its electrical conductivity is relatively poor for a metal.
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Titanium is a gray metal of low density, only 60% more than that of [[aluminium]], but is twice as strong. It is a common refractory material, and prized for its mechanical properties. It is slightly [[paramagnetism|paramagnetic]] and exists in three [[allotrope]]s. Its electrical conductivity is relatively poor for a metal.
  
 
===Chemical properties===
 
===Chemical properties===
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Titanium(III) compounds are also accessible to the amateur. When added to hot concentrated hydrochloric acid, titanium dissolves to form [[titanium(III) chloride]], which exists as a purple solution. Most titanium(III) compounds are bluish-purple due to the lone d electron, however, this purple color is not very strong due to the low probability of the transition. This is a good starting point for the production of many titanium compounds, such as [[titanium(III) oxide]]. Mixed titanium(III,IV) fluoro complexes can be produced, though they have not been studied well.
 
Titanium(III) compounds are also accessible to the amateur. When added to hot concentrated hydrochloric acid, titanium dissolves to form [[titanium(III) chloride]], which exists as a purple solution. Most titanium(III) compounds are bluish-purple due to the lone d electron, however, this purple color is not very strong due to the low probability of the transition. This is a good starting point for the production of many titanium compounds, such as [[titanium(III) oxide]]. Mixed titanium(III,IV) fluoro complexes can be produced, though they have not been studied well.
 +
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The metal also dissolves quite easily in hot, 50 w% sulphuric acid, forming purple Ti(III) sulphate. Stable solutions up to about 30 w% of Ti<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub> can be obtained this way. When CsCl solution is added to these solutions CsTi(III) alum precipitates.
  
 
Titanium(II) compounds also exist, but these are very difficult to produce, as they reduce many materials, including water.
 
Titanium(II) compounds also exist, but these are very difficult to produce, as they reduce many materials, including water.
  
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==Preparation==
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==Isolation==
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Titanium can be prepared by reducing [[titanium tetrachloride]] with magnesium, though this reaction is difficult for the amateur chemist as both titanium and its chloride are sensitive to water and air. Industrially, this reaction is performed in vacuum.
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Titanium can be prepared by reducing [[Titanium(IV) chloride|titanium tetrachloride]] with [[magnesium]], though this reaction is difficult for the amateur chemist as both titanium and its chloride are sensitive to water and air. Industrially, this reaction is performed in vacuum (Kroll process).
  
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An easier route to preparing titanium metal is through a thermite reaction between [[titanium dioxide]] and aluminium. The reaction doesn't proceed smoothly on its own, however, and instead must be boosted with a side reaction between aluminium and [[calcium sulfate]], or some other booster. If large nodules of the metal are desired, about one part [[calcium fluoride]] per every two parts titanium dioxide can be used to help the mixture melt together.
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An easier route to preparing titanium metal is through a thermite reaction between [[titanium dioxide]] and [[aluminium]]. The reaction doesn't proceed smoothly on its own, however, and instead must be boosted with a side reaction between aluminium and [[calcium sulfate]], or some other booster. If large nodules of the metal are desired, about one part [[calcium fluoride]] per every two parts titanium dioxide can be used to help the mixture melt together. The resulting titanium contains about 10 % of Al, some as alloyed metal, some as alumina slag inclusions. The obtained Ti is also non-ductile, as ductile Ti can only be obtained by the anaerobic Kroll process.
  
 
==Availability==
 
==Availability==
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===Storage===
 
===Storage===
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No special storage is required for titanium. Powdereded titanium however should be stored in a low oxygen container.
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No special storage is required for titanium. Powdered titanium however should be stored in a low oxygen container.
  
 
===Disposal===
 
===Disposal===

Latest revision as of 16:40, 28 April 2018

Titanium,  22Ti
Titanium shavings.jpg
Titanium shavings.
General properties
Name, symbol Titanium, Ti
Pronunciation /tɪˈteɪniəm/
Appearance Silvery white
Titanium in the periodic table
-
↑
Ti
↓
Zr
Scandium ← Titanium → Vanadium
Atomic number 22
Standard atomic weight (Ar) 47.87
Group, block 4; d-block
Period period 4
Electron configuration [Ar] 3d2 4s2
per shell
 2, 8, 10, 2
Physical properties
silvery,metalic
Phase solid
Melting point 1941 K ​(1668 °C, ​​3034 °F)
Boiling point 3560 K ​(3287 °C, ​5949 °F)
Density near r.t. 4.506 g/cm3
when liquid, at  4.11 g/cm3
Heat of fusion 14.15 kJ/mol
Heat of 425 kJ/mol
Molar heat capacity 25.060 J/(mol·K)
 pressure
Atomic properties
Oxidation states 4, 3, 2, 1, −1, −2 ​(an amphoteric oxide)
Electronegativity Pauling scale: 1.54
energies 1st: 658.8 kJ/mol
2nd: 1309.8 kJ/mol
3rd: 2652.5 kJ/mol
Atomic radius empirical: 147 pm
Covalent radius 160±8 pm
Miscellanea
Crystal structure ​

hexagonal close-packed (hcp)
Speed of sound thin rod 5090 m/s (at )
Thermal expansion 8.6 µm/(m·K) (at 25 °C)
Thermal conductivity 21.9 W/(m·K)
Electrical resistivity 420 Ω·m (at 20 °C)
Magnetic ordering Paramagnetic
Young's modulus 116 GPa
Shear modulus 44 GPa
Bulk modulus 110 GPa
Poisson ratio 0.32
Mohs hardness 6.0
Vickers hardness 830–3420 MPa
Brinell hardness 716–2770 MPa
CAS Registry Number 7440-32-6
History
Discovery William Gregor (1791)
First isolation Jöns Jakob Berzelius (1825)
Named by Martin Heinrich Klaproth (1795)
· references

Titanium is a transition metal with the symbol Ti and the atomic number 22. It is a grayish, light metal that has high corrosion resistance, but can be converted to multiple oxidation states, most commonly +4 and +3.

Properties

Physical properties

Titanium is a gray metal of low density, only 60% more than that of aluminium, but is twice as strong. It is a common refractory material, and prized for its mechanical properties. It is slightly paramagnetic and exists in three allotropes. Its electrical conductivity is relatively poor for a metal.

Chemical properties

Although titanium does not appear to be reactive, as it does not corrode and generally resists attack by concentrated acids or bases, it has a very strong affinity to oxygen. Its reactivity is masked by the formation of a passivating oxide layer of titanium dioxide on the surface. Titanium will ignite at temperatures exceeding 1,200 °C to form the oxide and nitride in air. Therefore, melting titanium must be done in an inert atmosphere. The flame is white, but slightly yellowish compared to a magnesium flame.

Titanium(IV) is the most common oxidation state of the element. Compounds of titanium(IV) are extremely difficult to dissolve in aqueous solution as the TiO2+ (titanyl) ion only exists in highly acidic conditions. However, it can be produced very easily. The most common titanium(IV) compound is the oxide. Titanium(IV) chloride is a powerful Lewis acid that hydrolyzes to hydrogen chloride and titanium dioxide in the presence of water. Titanium(IV) also forms stable peroxo complexes, which are quite colorful.

Titanium(III) compounds are also accessible to the amateur. When added to hot concentrated hydrochloric acid, titanium dissolves to form titanium(III) chloride, which exists as a purple solution. Most titanium(III) compounds are bluish-purple due to the lone d electron, however, this purple color is not very strong due to the low probability of the transition. This is a good starting point for the production of many titanium compounds, such as titanium(III) oxide. Mixed titanium(III,IV) fluoro complexes can be produced, though they have not been studied well.

The metal also dissolves quite easily in hot, 50 w% sulphuric acid, forming purple Ti(III) sulphate. Stable solutions up to about 30 w% of Ti2(SO4)3 can be obtained this way. When CsCl solution is added to these solutions CsTi(III) alum precipitates.

Titanium(II) compounds also exist, but these are very difficult to produce, as they reduce many materials, including water.

Isolation

Titanium can be prepared by reducing titanium tetrachloride with magnesium, though this reaction is difficult for the amateur chemist as both titanium and its chloride are sensitive to water and air. Industrially, this reaction is performed in vacuum (Kroll process).

An easier route to preparing titanium metal is through a thermite reaction between titanium dioxide and aluminium. The reaction doesn't proceed smoothly on its own, however, and instead must be boosted with a side reaction between aluminium and calcium sulfate, or some other booster. If large nodules of the metal are desired, about one part calcium fluoride per every two parts titanium dioxide can be used to help the mixture melt together. The resulting titanium contains about 10 % of Al, some as alloyed metal, some as alumina slag inclusions. The obtained Ti is also non-ductile, as ductile Ti can only be obtained by the anaerobic Kroll process.

Availability

Anodized titanium earrings

Titanium is available in over 50 grades. Grades 1 through 4 are pure titanium, with the largest impurity being oxygen atom replacements in the crystal lattice. The other grades are titanium alloys.

Projects

  • Titanium salutes, sparklers, and other pyrotechnics
  • Thermite boosed with calcium sulfate
  • Titanium tetrachloride synthesis
  • Titanium electrodes
  • Titanium halogen salts
  • Anodizing titanium metal produces a wide range of colors:

Handling

Safety

Titanium powder and turnings can be flammable. Finely dispersed titanium dust can ignite spontaneously with electrical sparks or open flames, causing a flashover. Bulk titanium, however, is extremely difficult to ignite.

Storage

No special storage is required for titanium. Powdered titanium however should be stored in a low oxygen container.

Disposal

Titanium and titanium compounds are non-toxic and do not require special disposal.

References

Relevant Sciencemadness threads

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