Difference between revisions of "Ytterbium"

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[[File:Ytterbium 4k.jpg|thumb|A piece of ytterbium metal]]
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{{Infobox element
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'''Ytterbium''' is a [[lanthanide]] with the symbol '''Yb''' and atomic number 70. It is a hard, silvery metal, sometimes described as slightly brassy, that is about as reactive as [[magnesium]]. It is not a particularly interesting addition to the amateur chemist's lab, but it and its ytterbium(II) derivatives are powerful [[Reducing agent|reducing agents]] that can be used in organic synthesis as an alternative to [[samarium]] and its samarium(II) derivatives.
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|image name=Ytterbium 4k.jpg
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|image alt=
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|image name comment=A piece of ytterbium metal
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|image name 2=
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|image alt 2=
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<!-- General properties -->
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|name=Ytterbium
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|symbol=Yb
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|pronounce=
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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=Metallic cream
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<!-- Periodic table -->
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|above=-
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|below=No
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|left=[[Thulium]]
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|right=[[Lutetium]]
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|number=70
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|atomic mass=173.045(10)
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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=
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|period=6
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|period ref=
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|period comment=
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|block=f
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|block ref=
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|block comment=
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|electron configuration=[Xe] 4f<sup>14</sup> 6s<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, 18, 32, 8, 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-white
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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=1097
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|melting point C=824
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|melting point F=1515
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|melting point ref=
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|melting point comment=
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|boiling point K=1469
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|boiling point C=1196
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|boiling point F=​2185
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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=6.90
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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=6.21
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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=7.66
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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=129
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|heat vaporization ref=
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|heat vaporization comment=
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|heat capacity=26.74
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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=736
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|vapor pressure 10=813
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|vapor pressure 100=910
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|vapor pressure 1 k=1047
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|vapor pressure 10 k=(1266)
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|vapor pressure 100 k=(1465)
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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='''3''', 2, 1
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|oxidation states ref=
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|oxidation states comment=(a basic oxide)
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|electronegativity=1.1
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|electronegativity ref=
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|electronegativity comment=
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|ionization energy 1=603.4
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|ionization energy 1 ref=
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|ionization energy 1 comment=
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|ionization energy 2=1174.8
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|ionization energy 2 ref=
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|ionization energy 2 comment=
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|ionization energy 3=2417
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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=176
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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=187±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=Face-centered cubic (fcc)
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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=1590
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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.=
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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=26.3
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|thermal expansion ref=
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|thermal expansion comment=(β, poly)
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|thermal expansion at 25=
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|thermal expansion at 25 ref=
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|thermal expansion at 25 comment=
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|thermal conductivity=38.5
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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=2.5·<sup>-7</sup>
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|electrical resistivity unit prefix=
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|electrical resistivity ref=
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|electrical resistivity comment=(β, poly)
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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=
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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=23.9
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|Young's modulus ref=
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|Young's modulus comment=(β form)
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|Shear modulus=9.9
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|Shear modulus ref=
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|Shear modulus comment=(β form)
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|Bulk modulus=30.5
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|Bulk modulus ref=
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|Bulk modulus comment=(β form)
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|Poisson ratio=0.207
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|Poisson ratio ref=
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|Poisson ratio comment=(β form)
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|Mohs hardness=
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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=205–250
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|Vickers hardness ref=
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|Vickers hardness comment=
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|Brinell hardness=340–440
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|Brinell hardness ref=
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|Brinell hardness comment=
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|CAS number=7440-64-4
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|CAS number ref=
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|CAS number comment=
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<!-- History -->
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|naming=After Ytterby (Sweden), where it was mined
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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=Jean Charles Galissard de Marignac
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|discovery date ref=
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|discovery date=1878
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|first isolation by=Carl Auer von Welsbach
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|first isolation date ref=
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|first isolation date=1906
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|discovery and first isolation by=
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|named by=
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|named date ref=
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|named date=
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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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'''Ytterbium''' is a [[lanthanide]] with the symbol '''Yb''' and atomic number 70. It is a hard, silvery metal, sometimes described as slightly brassy, that is about as reactive as [[magnesium]]. It is not a particularly interesting addition to the amateur chemist's lab, but it and its ytterbium(II) derivatives are powerful [[Reducer|reducing agents]] that can be used in organic synthesis as an alternative to [[samarium]] and its samarium(II) derivatives.
  
 
==Properties==
 
==Properties==
 
===Physical properties===
 
===Physical properties===
−
Ytterbium is a silvery metal. Its exact color, however, is disputed: some sources describe it as grayish, others as slightly brassy. It exists in three [[Allotrope|allotropes]]: α-ytterbium, which exists in a hexagonal crystal structure is stable below -13 °C and is [[Diamagnetism|diamagnetic]], β-ytterbium, which is stable at room temperature, [[Paramagnetism|paramagnetic]] and exists in a face-centered cubic structure, and γ-ytterbium, which exists above 795 °C and has a body centered cubic structure.
+
Ytterbium is a slightly brassy metal, sometimes found darkened as it slowly tarnishes in air over the course of months or years. It exists in three [[allotrope]]s: α-ytterbium, which exists in a hexagonal crystal structure is stable below -13 °C and is [[Diamagnetism|diamagnetic]], β-ytterbium, which is stable at room temperature, [[Paramagnetism|paramagnetic]] and exists in a face-centered cubic structure, and γ-ytterbium, which exists above 795 °C and has a body centered cubic structure.
  
−
Due to the filled f-shell, the metal has an unusually low melting and boiling point (824 °C and 1196 °C respectively), and is also less dense than most other lanthanides. Melting ytterbium (which must be done in an inert atmosphere to prevent ignition of the metal) will invariably cause some to boil off due to the narrow liquid range. This filled f-shell contributes to ytterbium's extremely low magnetism compared to rare earths such as [[Gadolinium|gadolinium]], [[terbium]] and [[Dysprosium|dysprosium]].
+
Ytterbium can be thought of as analogous to zinc in terms of its relation to the other lanthanides. Due to the filled f-shell, the metal has an unusually low melting and boiling point (824 °C and 1196 °C respectively), and is also less dense than most other lanthanides. Melting ytterbium (which must be done in an inert atmosphere to prevent ignition of the metal) will invariably cause some to boil off due to the narrow liquid range. This filled f-shell contributes to ytterbium's extremely low magnetism compared to rare earths such as [[gadolinium]], [[terbium]] and [[dysprosium]]. However, fine ytterbium powder can be picked up by a neodymium magnet.
  
−
Ytterbium metal changes its resisitivity as pressure or other stresses increase.
+
Ytterbium is also notoriously soft and sticky. Although filing ytterbium into powder is easier than it is for other lanthanides, it will leave traces of itself behind in the grooves of the file, and it is nearly impossible to remove once situated there. It is best to dedicate a file to ytterbium and use a different file for other elements to limit contamination.
  
 
===Chemical properties===
 
===Chemical properties===
−
Ytterbium is a reactive metal, but it does not tarnish quickly in air due to passivation. It does, however, burn in air to form ytterbium(III) oxide. Ytterbium burns with a characteristic green flame, notably in compositions with [[Hexachloroethane|hexachloroethane]] and [[Polytetrafluoroethylene|polytetrafluoroethylene]].
+
Ytterbium is a reactive metal, but it does not tarnish quickly in air, taking months or years to do so, and unless stored with complete disregard for its properties, rarely corrodes to the oxide. It does, however, burn in air to form ytterbium(III) oxide. Ytterbium powder burns with a characteristic green flame, notably in compositions with [[hexachloroethane]] and [[Polytetrafluoroethylene|PTFE]].
  
−
Ytterbium reacts vigorously with dilute acids to form [[Salt|salts]]. Most of these salts are soluble in water except for the fluoride and oxalate. All of these salts are white in color. Ytterbium also reacts with the [[Halogen|halogens]] to form trihalides. The metal reacts only slowly in cold water, but vigorously in hot water, to form ytterbium hydroxide, which is [[Base|basic]] enough to absorb carbon dioxide from the air to form [[ytterbium carbonate]].
+
Ytterbium reacts vigorously with dilute acids to form [[Salt|salts]]. Most of these salts are soluble in water except for the fluoride and oxalate. All of these salts are white in color. Ytterbium also reacts with the [[halogen|halogens]] to form trihalides. The metal reacts only slowly in cold water, but vigorously in hot water, to form ytterbium hydroxide, which is [[Base|basic]] enough to absorb carbon dioxide from the air to form [[ytterbium carbonate]].
  
−
Under reducing conditions, a ytterbium(II) species is known to exist. This ion will reduce water to [[Hydrogen|hydrogen]] gas and is therefore unstable in aqueous solution. It can be isolated in [[Tetrahydrofuran|tetrahydrofuran]]. Ytterbium(II) compounds can be formed by reacting metallic ytterbium with ytterbium(III) compounds, but they [[Disproportionation|disproportionate]] to ytterbium metal and ytterbium(III) compounds at elevated temperatures.
+
Under reducing conditions, ytterbium(II) species is known to exist. This ion will reduce water to [[Hydrogen|hydrogen]] gas and is therefore unstable in aqueous solution, but it is present long enough to be detected. It can be isolated in [[tetrahydrofuran]]. Ytterbium(II) compounds can be formed by reacting metallic ytterbium with ytterbium(III) compounds, but they [[Disproportionation|disproportionate]] back to ytterbium metal and ytterbium(III) compounds at elevated temperatures.
 +
 
 +
In glacial acetic acid, ytterbium dissolves slowly and forms an orange solution, likely an ytterbium(II) acetato complex. Adding water considerably increases the rate of reaction and limits the formation of the orange species. The resulting ytterbium(III) acetate tetrahydrate forms large rhombic crystals after slow evaporation.
  
 
==Availability==
 
==Availability==
−
Ytterbium is more common than iodine on Earth, but it is very hard to find and expensive. One source for ytterbium, as well as other rare earth metals, is [http://www.elementsales.com/pl_element.htm#yb Metallium]. It is sold in 5 gram and 20 gram sizes, as well as rods, ampoules, and coins. Ytterbium and its compounds are occasionally sold on eBay as well.
+
Ytterbium is more common than iodine on Earth, but it is very hard to find and relatively expensive. One source for ytterbium, as well as other rare earth metals, is [http://www.elementsales.com/pl_element.htm#yb Metallium]. It is sold in 5 gram and 20 gram sizes, as well as rods, ampoules, and coins. Ytterbium and its compounds are occasionally sold on eBay as well.
  
 
==Projects==
 
==Projects==
Line 27: Line 300:
 
===Safety===
 
===Safety===
 
====Toxicity====
 
====Toxicity====
−
Ytterbium compounds have not been investigated for their toxicity, and should be treated as mildly toxic. Ytterbium has no biological role but may stimulate metabolism. Salts of ytterbium, especially the halides, tend to hydrolyze at elevated temperatures and may emit noxious or strongly acidic vapors.
+
Ytterbium compounds have not been investigated for their toxicity, and should be treated as mildly toxic. Ytterbium has no biological role but may stimulate metabolism. Salts of ytterbium, especially the halides, tend to hydrolyze at elevated temperatures and may emit noxious or strongly acidic vapors (commonly HCl in the case of ytterbium(III) chloride).
  
 
====Flammability====
 
====Flammability====
−
Ytterbium as small pieces will ignite in the presence of an open flame, and ytterbium dust and powder may ignite very easily. Ytterbium and [[thulium]] fires may be identified by their brilliant green flames. Class D [[Fire extinguisher|fire extingushers]] should be at hand. Water may aggravate burning ytterbium and should never be used.
+
Ytterbium as small pieces will ignite in the presence of an open flame, and ytterbium dust and powder may ignite very easily. Ytterbium and [[thulium]] fires may be identified by their brilliant green flames. Class D [[Fire extinguisher|fire extinguishers]] should be at hand. Water may aggravate burning ytterbium and should never be used to put out the flame.
  
 
===Storage===
 
===Storage===
−
Ytterbium should be stored in closed containers, away from any corrosive chemicals.
+
Ytterbium should be stored in closed containers, away from any acids and oxidizing agents, particularly volatile ones. It is stable in air almost indefinitely, but does tarnish slowly.
  
 
===Disposal===
 
===Disposal===

Latest revision as of 15:52, 7 May 2021

Ytterbium,  70Yb
Ytterbium 4k.jpg
A piece of ytterbium metal
General properties
Name, symbol Ytterbium, Yb
Appearance Metallic cream
Ytterbium in the periodic table
-
↑
Yb
↓
No
Thulium ← Ytterbium → Lutetium
Atomic number 70
Standard atomic weight (Ar) 173.045(10)
Group, block , f-block
Period period 6
Electron configuration [Xe] 4f14 6s2
per shell
 2, 8, 18, 32, 8, 2
Physical properties
Silvery-white
Phase Solid
Melting point 1097 K ​(824 °C, ​1515 °F)
Boiling point 1469 K ​(1196 °C, ​​2185 °F)
Density near r.t. 6.90 g/cm3
when liquid, at  6.21 g/cm3
Heat of fusion 7.66 kJ/mol
Heat of 129 kJ/mol
Molar heat capacity 26.74 J/(mol·K)
 pressure
Atomic properties
Oxidation states 3, 2, 1 ​(a basic oxide)
Electronegativity Pauling scale: 1.1
energies 1st: 603.4 kJ/mol
2nd: 1174.8 kJ/mol
3rd: 2417 kJ/mol
Atomic radius empirical: 176 pm
Covalent radius 187±8 pm
Miscellanea
Crystal structure ​Face-centered cubic (fcc)
Speed of sound thin rod 1590 m/s (at 20 °C)
Thermal expansion 26.3 µm/(m·K) (β, poly)
Thermal conductivity 38.5 W/(m·K)
Electrical resistivity 2.5·-7 Ω·m (β, poly)
Magnetic ordering Paramagnetic
Young's modulus 23.9 GPa (β form)
Shear modulus 9.9 GPa (β form)
Bulk modulus 30.5 GPa (β form)
Poisson ratio 0.207 (β form)
Vickers hardness 205–250 MPa
Brinell hardness 340–440 MPa
CAS Registry Number 7440-64-4
History
Naming After Ytterby (Sweden), where it was mined
Discovery Jean Charles Galissard de Marignac (1878)
First isolation Carl Auer von Welsbach (1906)
· references

Ytterbium is a lanthanide with the symbol Yb and atomic number 70. It is a hard, silvery metal, sometimes described as slightly brassy, that is about as reactive as magnesium. It is not a particularly interesting addition to the amateur chemist's lab, but it and its ytterbium(II) derivatives are powerful reducing agents that can be used in organic synthesis as an alternative to samarium and its samarium(II) derivatives.

Properties

Physical properties

Ytterbium is a slightly brassy metal, sometimes found darkened as it slowly tarnishes in air over the course of months or years. It exists in three allotropes: α-ytterbium, which exists in a hexagonal crystal structure is stable below -13 °C and is diamagnetic, β-ytterbium, which is stable at room temperature, paramagnetic and exists in a face-centered cubic structure, and γ-ytterbium, which exists above 795 °C and has a body centered cubic structure.

Ytterbium can be thought of as analogous to zinc in terms of its relation to the other lanthanides. Due to the filled f-shell, the metal has an unusually low melting and boiling point (824 °C and 1196 °C respectively), and is also less dense than most other lanthanides. Melting ytterbium (which must be done in an inert atmosphere to prevent ignition of the metal) will invariably cause some to boil off due to the narrow liquid range. This filled f-shell contributes to ytterbium's extremely low magnetism compared to rare earths such as gadolinium, terbium and dysprosium. However, fine ytterbium powder can be picked up by a neodymium magnet.

Ytterbium is also notoriously soft and sticky. Although filing ytterbium into powder is easier than it is for other lanthanides, it will leave traces of itself behind in the grooves of the file, and it is nearly impossible to remove once situated there. It is best to dedicate a file to ytterbium and use a different file for other elements to limit contamination.

Chemical properties

Ytterbium is a reactive metal, but it does not tarnish quickly in air, taking months or years to do so, and unless stored with complete disregard for its properties, rarely corrodes to the oxide. It does, however, burn in air to form ytterbium(III) oxide. Ytterbium powder burns with a characteristic green flame, notably in compositions with hexachloroethane and PTFE.

Ytterbium reacts vigorously with dilute acids to form salts. Most of these salts are soluble in water except for the fluoride and oxalate. All of these salts are white in color. Ytterbium also reacts with the halogens to form trihalides. The metal reacts only slowly in cold water, but vigorously in hot water, to form ytterbium hydroxide, which is basic enough to absorb carbon dioxide from the air to form ytterbium carbonate.

Under reducing conditions, ytterbium(II) species is known to exist. This ion will reduce water to hydrogen gas and is therefore unstable in aqueous solution, but it is present long enough to be detected. It can be isolated in tetrahydrofuran. Ytterbium(II) compounds can be formed by reacting metallic ytterbium with ytterbium(III) compounds, but they disproportionate back to ytterbium metal and ytterbium(III) compounds at elevated temperatures.

In glacial acetic acid, ytterbium dissolves slowly and forms an orange solution, likely an ytterbium(II) acetato complex. Adding water considerably increases the rate of reaction and limits the formation of the orange species. The resulting ytterbium(III) acetate tetrahydrate forms large rhombic crystals after slow evaporation.

Availability

Ytterbium is more common than iodine on Earth, but it is very hard to find and relatively expensive. One source for ytterbium, as well as other rare earth metals, is Metallium. It is sold in 5 gram and 20 gram sizes, as well as rods, ampoules, and coins. Ytterbium and its compounds are occasionally sold on eBay as well.

Projects

  • Making and using ytterbium(II) compounds
  • Green-burning energetic mixtures

Handling

Safety

Toxicity

Ytterbium compounds have not been investigated for their toxicity, and should be treated as mildly toxic. Ytterbium has no biological role but may stimulate metabolism. Salts of ytterbium, especially the halides, tend to hydrolyze at elevated temperatures and may emit noxious or strongly acidic vapors (commonly HCl in the case of ytterbium(III) chloride).

Flammability

Ytterbium as small pieces will ignite in the presence of an open flame, and ytterbium dust and powder may ignite very easily. Ytterbium and thulium fires may be identified by their brilliant green flames. Class D fire extinguishers should be at hand. Water may aggravate burning ytterbium and should never be used to put out the flame.

Storage

Ytterbium should be stored in closed containers, away from any acids and oxidizing agents, particularly volatile ones. It is stable in air almost indefinitely, but does tarnish slowly.

Disposal

Best to try to recycle it.

References

Relevant Sciencemadness threads

None as of yet - why not start some research on this element?

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