Difference between revisions of "Carbon"

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'''Carbon''' is a nonmetallic chemical element with symbol C and atomic number 6. It is well known for its numerous [[Allotrope|allotropes]], including diamond and graphite and as being central to all life. Because carbon can easily form four single bonds, it is capable of forming a vast number of compounds, namely all [[organic compounds]].
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{{Infobox element
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<!-- top -->
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|image name=Carbon.jpg
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|image alt=
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|image size=
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|image name comment=Native carbon - graphite
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|image name 2=Diamant.jpg
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|image alt 2=
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|image size 2=
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|image name 2 comment=Small diamonds from grinding wheel
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<!-- General properties -->
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|name=Carbon
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|symbol=C
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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=Amorphous carbon, diamond, fullerene, graphene, glassy carbon, graphite, nanotubes, pyrolytic carbon
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|appearance=Clear (diamond)<br>Black or dark gray (all others)
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<!-- Periodic table -->
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|above=-
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|below=[[Silicon|Si]]
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|left=[[Boron]]
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|right=[[Nitrogen]]
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|number=6
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|atomic mass=12.011
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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=14
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|group ref=
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|group comment=(carbon group)
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|period=2
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|period ref=
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|period comment=
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|block=p
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|block ref=
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|block comment=
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|electron configuration=[He] 2s<sup>2</sup> 2p<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, 4
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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=Black, gray, transparent
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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=
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|melting point C=
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|melting point F=
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|melting point ref=
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|melting point comment=
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|boiling point K=
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|boiling point C=
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|boiling point F=
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|boiling point ref=
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|boiling point comment=
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|sublimation point K=3915
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|sublimation point C=3642
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|sublimation point F=6588
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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=
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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=''amorphous'': 1.8–2.1 g/cm<sup>3</sup><br>''graphite'': 2.267 g/cm<sup>3</sup><br>''diamond'': 3.515 g/cm<sup>3</sup>
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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=
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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=4600
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|triple point kPa=​10,800
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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=117
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|heat fusion ref=
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|heat fusion comment=(graphite)
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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=
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|heat vaporization ref=
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|heat vaporization comment=
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|heat capacity=
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|heat capacity ref=
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|heat capacity comment=6.155 J/(mol·K) (diamond)<br>8.517 J/(mol·K) (graphite)
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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=
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|vapor pressure 10=
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|vapor pressure 100=
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|vapor pressure 1 k=
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|vapor pressure 10 k=
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|vapor pressure 100 k=
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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, 0, −1, −2, −3, '''−4'''
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|oxidation states ref=(a mildly acidic oxide)
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|oxidation states comment=
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|electronegativity=2.55
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|electronegativity ref=
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|electronegativity comment=
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|ionization energy 1=1086.5
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|ionization energy 1 ref=
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|ionization energy 1 comment=
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|ionization energy 2=2352.6
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|ionization energy 2 ref=
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|ionization energy 2 comment=
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|ionization energy 3=4620.5
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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=
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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=
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|covalent radius ref=
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|covalent radius comment=sp<sup>3</sup>: 77 pm<br>sp<sup>2</sup>: 73 pm<br>sp: 69 pm
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|Van der Waals radius=170
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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=graphite: ​simple hexagonal<br>diamond: ​face-centered diamond-cubic
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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=18,350
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|speed of sound rod at 20 ref=
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|speed of sound rod at 20 comment= (diamond)
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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=
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|thermal expansion ref=
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|thermal expansion comment=
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|thermal expansion at 25=0.8
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|thermal expansion at 25 ref=
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|thermal expansion at 25 comment=(diamond)
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|thermal conductivity=
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|thermal conductivity ref=
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|thermal conductivity comment=graphite: 119–165 W/(m·K)<br>diamond: 900–2,300 W/(m·K)
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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=7.837·10<sup>-9</sup>
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|electrical resistivity unit prefix=
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|electrical resistivity ref=
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|electrical resistivity comment=(graphite)
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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=Diamagnetic
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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=1050
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|Young's modulus ref=
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|Young's modulus comment=(diamond)
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|Shear modulus=478
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|Shear modulus ref=
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|Shear modulus comment=(diamond)
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|Bulk modulus=442
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|Bulk modulus ref=
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|Bulk modulus comment=(diamond)
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|Poisson ratio=0.1
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|Poisson ratio ref=
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|Poisson ratio comment=(diamond)
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|Mohs hardness=1–2(graphite)<br>10 (diamond)
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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=
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|Vickers hardness ref=
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|Vickers hardness comment=
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|Brinell hardness=
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|Brinell hardness ref=
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|Brinell hardness comment=
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|CAS number=7440-44-0
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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=Egyptians and Sumerians (3750 BCE)
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|discovery date ref=
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|discovery date=
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|first isolation by=
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|first isolation date ref=
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|first isolation date=
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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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'''Carbon''' is a nonmetallic chemical element with symbol '''C''' and atomic number 6. It is well known for its numerous [[allotrope]]s, including diamond and graphite and as being central to all life. Because carbon can easily form four single bonds, it is capable of forming a vast number of compounds, namely all [[organic compound]]s.
  
 
==Properties==
 
==Properties==
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Carbon is not very reactive at standard conditions. It will burn in oxygen, the grade of oxidation greatly depending on the allotrope used as well as particle size and oxygen concentration.
 
Carbon is not very reactive at standard conditions. It will burn in oxygen, the grade of oxidation greatly depending on the allotrope used as well as particle size and oxygen concentration.
  
−
:C + O<sub>2</sub> → [[carbon dioxide|CO<sub>2</sub>]]
+
: C + O<sub>2</sub> → [[carbon dioxide|CO<sub>2</sub>]]
  
 
It will reduce the oxides of metals low on the reactivity scale to pure element, and forms carbides with more reactive metals:
 
It will reduce the oxides of metals low on the reactivity scale to pure element, and forms carbides with more reactive metals:
  
−
:2 [[Iron(III) oxide|Fe<sub>2</sub>O<sub>3</sub>]] + 3 C → 4 [[iron|Fe]] + 3 CO<sub>2</sub>
+
:2 [[Iron(III) oxide|Fe<sub>2</sub>O<sub>3</sub>]] + 3 C → 4 [[Iron|Fe]] + 3 CO<sub>2</sub>
−
:2 [[aluminium oxide|Al<sub>2</sub>O<sub>3</sub>]] + 9 C → Al<sub>4</sub>C<sub>3</sub> + 6 [[Carbon monoxide|CO]]
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:2 [[Aluminium oxide|Al<sub>2</sub>O<sub>3</sub>]] + 9 C → Al<sub>4</sub>C<sub>3</sub> + 6 [[Carbon monoxide|CO]]
−
Carbon can also reduce [[Carbonates|carbonates]] to their metals and [[Carbon dioxide|carbon dioxide]]:
+
  
−
:2[[Copper(II) carbonate|CuCO<sub>3</sub>]] + C → 2[[Copper|Cu]] + 3CO<sub>2</sub><ref>https://www.youtube.com/watch?v=g3ar6zGcTQY</ref>
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Carbon can also reduce [[carbonate]]s to their metals and [[carbon dioxide]]:
 +
 
 +
:2 [[Copper(II) carbonate|CuCO<sub>3</sub>]] + C → 2[[Copper|Cu]] + 3CO<sub>2</sub><ref>https://www.youtube.com/watch?v=g3ar6zGcTQY</ref>
 
Activated carbon, a form of amorphous carbon with an extremely high surface-area-to-mass ratio, is used as an [[adsorption|adsorbent]] in gas masks and can be used as a catalyst for some chemical reactions.
 
Activated carbon, a form of amorphous carbon with an extremely high surface-area-to-mass ratio, is used as an [[adsorption|adsorbent]] in gas masks and can be used as a catalyst for some chemical reactions.
  
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*'''Graphite''': One of the most common allotropes of carbon, it's black-grey, is a fairly good electrical conductor, but has low thermal conductivity. Because carbon has one of the highest boiling temperature, it can be used in electrical arc lamp electrodes. Under standard conditions, graphite is the most stable form of carbon. It will burn under strong oxidizing conditions, but it's not very reactive otherwise.
 
*'''Graphite''': One of the most common allotropes of carbon, it's black-grey, is a fairly good electrical conductor, but has low thermal conductivity. Because carbon has one of the highest boiling temperature, it can be used in electrical arc lamp electrodes. Under standard conditions, graphite is the most stable form of carbon. It will burn under strong oxidizing conditions, but it's not very reactive otherwise.
  
−
*'''Diamond''': By far the most known allotrope of carbon. Transparent, it's the hardest known natural mineral, has the highest thermal conductivity of any known natural material, but unlike graphite, it's an electrical insulator. It is much more resistant to chemical attacks than graphite.
+
*'''Diamond''': By far the most known allotrope of carbon. A transparent material, it's the hardest known natural mineral, has the highest thermal conductivity of any known natural material, but unlike graphite, it's an electrical insulator. It is much more resistant to chemical attack than graphite.
  
 
*'''Amorphous carbon''', which has a less defined structure than other forms, is black in color, and is much more reactive than the other allotropes. It is the largest component of some organic [[pyrolysis]] products such as charcoal.
 
*'''Amorphous carbon''', which has a less defined structure than other forms, is black in color, and is much more reactive than the other allotropes. It is the largest component of some organic [[pyrolysis]] products such as charcoal.
  
 
*'''Glassy carbon''', also known as '''vitreous carbon''', is a non-graphitizing carbon which combines glassy and ceramic properties with those of graphite. Similar to graphite, it's a good electrical conductor and it's used as electrodes in electrochemistry and as high temperature crucibles.
 
*'''Glassy carbon''', also known as '''vitreous carbon''', is a non-graphitizing carbon which combines glassy and ceramic properties with those of graphite. Similar to graphite, it's a good electrical conductor and it's used as electrodes in electrochemistry and as high temperature crucibles.
 +
 +
*'''Pyrolytic carbon''' is an artificial form of carbon, similar to graphite, but with some covalent bonding between its graphene sheets as a result of imperfections in its production. It displays cleavage, like mica. This material has some unusual properties, like being more thermally conductive along the cleavage plane than graphite and being strongly diamagnetic, capable of levitating in a magnetic field.
  
 
*'''Fullerenes''' are molecules composed of carbon, in various forms such as hollow spheres (buckyballs), tubes (nanotubes), etc. They're of little importance to the amateur chemist, but are often studied in physics due to their special properties.
 
*'''Fullerenes''' are molecules composed of carbon, in various forms such as hollow spheres (buckyballs), tubes (nanotubes), etc. They're of little importance to the amateur chemist, but are often studied in physics due to their special properties.
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==Availability==
 
==Availability==
−
Graphite can be either bought from stores, extracted from carbon batteries, or simply reusing old graphite electrodes. Diamond powder can be bought from stores that sell abrasive materials and larger stones if you have enough money. Amorphous carbon can be made from a variety of sources, such as dehydrating sugar with conc. [[sulfuric acid]], scraping the black powder that forms when reducing copper salts with steel (though it should be washed with acid to remove the black copper oxide). Glassy carbon can be bought online.
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Graphite can be either bought from stores, extracted from carbon batteries, or simply reusing old graphite electrodes.
 +
 
 +
Diamond powder can be bought from stores that sell abrasive materials and larger stones, though it is quite expensive.
 +
 
 +
Amorphous carbon can be made from a variety of sources, such as dehydrating sugar with conc. [[sulfuric acid]], scraping the black powder that forms when reducing copper salts with steel (though it should be washed with acid to remove the black copper oxide), pyrolyzing sugar, etc.
 +
 
 +
Glassy carbon can be bought online as electrodes.
  
 
==Preparation==
 
==Preparation==
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Amorphous carbon can be made by dehydrating sugar with sulfuric acid. Once it has been washed of excess acid, this is a very pure form of carbon.
 
Amorphous carbon can be made by dehydrating sugar with sulfuric acid. Once it has been washed of excess acid, this is a very pure form of carbon.
  
−
Diamond powder can be made by passing electrical current through graphite for a long period of time. Larger diamonds, let us know how you did it.
+
Diamond powder can be made by passing electrical current through graphite for a long period of time. Larger diamonds cannot be feasibly made in a nonindustrial setting.
  
−
Buckyballs are present in soot, though the percentage is very small.
+
Buckyballs are present in soot, though the percentage is insignificant. Commercially, they are prepared by extraction of the pyrolysis products of aromatic compounds, or by an arc discharge between two graphite electrodes.
  
 
==Projects==
 
==Projects==
 
* Various pyrotechnics and energetic materials, such as [[black powder]]
 
* Various pyrotechnics and energetic materials, such as [[black powder]]
−
* [[carbothermal reduction|Carbothermally reduce]] metallic oxides
+
* [[Carbothermal reduction|Carbothermally reduction]] of metal oxides
 
* Produce [[carbon monoxide]] from hot carbon and water
 
* Produce [[carbon monoxide]] from hot carbon and water
 
* Produce elemental [[phosphorus]] from carbon and [[phosphoric acid]] or from carbon, a phosphate salt, and [[silicon dioxide]]
 
* Produce elemental [[phosphorus]] from carbon and [[phosphoric acid]] or from carbon, a phosphate salt, and [[silicon dioxide]]
 
* Electrolysis (graphite and glassy carbon electrodes)
 
* Electrolysis (graphite and glassy carbon electrodes)
 +
* Demonstration of diamagnetism (pyrolytic carbon)
 +
* Make an arc furnace (graphite and glassy carbon)
  
 
==Handling==
 
==Handling==
 
===Safety===
 
===Safety===
−
Pure carbon has extremely low toxicity to humans and can be handled and even ingested safely in the form of graphite or charcoal, though not recommended.
+
Pure carbon has extremely low toxicity to humans and can be handled and even ingested safely in the form of graphite or charcoal, and USP charcoal is used for treating various medical conditions.
  
−
Inhalation of coal dust or soot (carbon black) in large quantities, however, can be dangerous, as it irritates lung tissues and causes various congestive lung diseases.
+
Inhalation of coal dust or soot (carbon black) in large quantities, however, can be dangerous, as it irritates lung tissues and causes various congestive lung diseases. Powdered diamond is highly abrasive, and proper protection must be worn when working with it.
  
 
===Storage===
 
===Storage===
−
No carbon allotrope requires any special storage. Amorphous carbon, however, if it has high specific surface area, may adsorb gasses from the air, such as volatile organic compounds (VOC) or acidic vapors and this will contaminate the purity of the carbon. Best stored in closed containers.
+
No carbon allotrope requires any special storage. Amorphous carbon, however, if it has high specific surface area, may adsorb gasses from the air, such as volatile organic compounds (VOC) or acidic vapors which will lower the purity of the carbon. It is best stored in tightly sealed containers.
  
 
===Disposal===
 
===Disposal===
−
Amorphous carbon can burn in an oxidizing atmosphere, but the other carbon allotropes burn only at high temperatures. Carbon traces from various glassware can be cleaned either with [[aqua regia]] or [[piranha solution]]. No common carbon allotrope poses any threat to the environment, so no special disposal is required when discarding carbon waste.
+
Amorphous carbon can burn in an oxidizing atmosphere, but the other carbon allotropes burn only at high temperatures. Carbon traces from various glassware can be cleaned either with [[aqua regia]] or [[piranha solution]]. No common carbon allotrope poses any threat to the environment, so no special disposal is required when discarding carbon waste and may be dumped in trash. Used industrial graphite electrodes may be contaminated with heavy metals and should be taken to disposal centers.
  
 
==References==
 
==References==
 
<references />
 
<references />
 
===Relevant Sciencemadness threads===
 
===Relevant Sciencemadness threads===
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=6768 Carbon allotropes... how many?]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=25189 Pyrolysis of sugar to make Carbon anodes]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=63192 Pyrolytic Carbon]
  
 
[[Category:Elements]]
 
[[Category:Elements]]
 
[[Category:Nonmetals]]
 
[[Category:Nonmetals]]
 +
[[Category:P-block]]
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[[Category:Reducing agents]]
 +
[[Category:Minerals]]

Latest revision as of 22:25, 26 August 2023

Carbon,  6C
Carbon.jpg
Native carbon - graphite
Diamant.jpg
Small diamonds from grinding wheel
General properties
Name, symbol Carbon, C
Allotropes Amorphous carbon, diamond, fullerene, graphene, glassy carbon, graphite, nanotubes, pyrolytic carbon
Appearance Clear (diamond)
Black or dark gray (all others)
Carbon in the periodic table
-
↑
C
↓
Si
Boron ← Carbon → Nitrogen
Atomic number 6
Standard atomic weight (Ar) 12.011
Group, block (carbon group); p-block
Period period 2
Electron configuration [He] 2s2 2p2
per shell
 2, 4
Physical properties
Black, gray, transparent
Phase Solid
Sublimation point 3915 K ​(3642 °C, ​6588 °F)
Triple point 4600 K, ​​10,800 kPa
Heat of fusion 117 kJ/mol (graphite)
Atomic properties
Oxidation states +4, +3, +2, +1, 0, −1, −2, −3, −4(a mildly acidic oxide)
Electronegativity Pauling scale: 2.55
energies 1st: 1086.5 kJ/mol
2nd: 2352.6 kJ/mol
3rd: 4620.5 kJ/mol
Van der Waals radius 170 pm
Miscellanea
Crystal structure ​graphite: ​simple hexagonal
diamond: ​face-centered diamond-cubic
Speed of sound thin rod 18,350 m/s (at 20 °C) (diamond)
Thermal expansion 0.8 µm/(m·K) (at 25 °C) (diamond)
Electrical resistivity 7.837·10-9 Ω·m (graphite)
Magnetic ordering Diamagnetic
Young's modulus 1050 GPa (diamond)
Shear modulus 478 GPa (diamond)
Bulk modulus 442 GPa (diamond)
Poisson ratio 0.1 (diamond)
Mohs hardness 1–2(graphite)
10 (diamond)
CAS Registry Number 7440-44-0
History
Discovery Egyptians and Sumerians (3750 BCE)
· references

Carbon is a nonmetallic chemical element with symbol C and atomic number 6. It is well known for its numerous allotropes, including diamond and graphite and as being central to all life. Because carbon can easily form four single bonds, it is capable of forming a vast number of compounds, namely all organic compounds.

Properties

Chemical

Carbon is not very reactive at standard conditions. It will burn in oxygen, the grade of oxidation greatly depending on the allotrope used as well as particle size and oxygen concentration.

C + O2 → CO2

It will reduce the oxides of metals low on the reactivity scale to pure element, and forms carbides with more reactive metals:

2 Fe2O3 + 3 C → 4 Fe + 3 CO2
2 Al2O3 + 9 C → Al4C3 + 6 CO

Carbon can also reduce carbonates to their metals and carbon dioxide:

2 CuCO3 + C → 2Cu + 3CO2[1]

Activated carbon, a form of amorphous carbon with an extremely high surface-area-to-mass ratio, is used as an adsorbent in gas masks and can be used as a catalyst for some chemical reactions.

Physical

Due to its valency, carbon is capable of forming many interesting allotropes. Historically there were only three well known allotropes (graphite, diamond, amorphous carbon), but over the years many more have been discovered and many more are hypothesized. Only the most important are described below:

  • Graphite: One of the most common allotropes of carbon, it's black-grey, is a fairly good electrical conductor, but has low thermal conductivity. Because carbon has one of the highest boiling temperature, it can be used in electrical arc lamp electrodes. Under standard conditions, graphite is the most stable form of carbon. It will burn under strong oxidizing conditions, but it's not very reactive otherwise.
  • Diamond: By far the most known allotrope of carbon. A transparent material, it's the hardest known natural mineral, has the highest thermal conductivity of any known natural material, but unlike graphite, it's an electrical insulator. It is much more resistant to chemical attack than graphite.
  • Amorphous carbon, which has a less defined structure than other forms, is black in color, and is much more reactive than the other allotropes. It is the largest component of some organic pyrolysis products such as charcoal.
  • Glassy carbon, also known as vitreous carbon, is a non-graphitizing carbon which combines glassy and ceramic properties with those of graphite. Similar to graphite, it's a good electrical conductor and it's used as electrodes in electrochemistry and as high temperature crucibles.
  • Pyrolytic carbon is an artificial form of carbon, similar to graphite, but with some covalent bonding between its graphene sheets as a result of imperfections in its production. It displays cleavage, like mica. This material has some unusual properties, like being more thermally conductive along the cleavage plane than graphite and being strongly diamagnetic, capable of levitating in a magnetic field.
  • Fullerenes are molecules composed of carbon, in various forms such as hollow spheres (buckyballs), tubes (nanotubes), etc. They're of little importance to the amateur chemist, but are often studied in physics due to their special properties.
  • Graphene forms nearly transparent sheets, only a single atom thick, of carbon atoms. It is 100 times stronger than steel and is an excellent conductor or both electricity and heat.

Availability

Graphite can be either bought from stores, extracted from carbon batteries, or simply reusing old graphite electrodes.

Diamond powder can be bought from stores that sell abrasive materials and larger stones, though it is quite expensive.

Amorphous carbon can be made from a variety of sources, such as dehydrating sugar with conc. sulfuric acid, scraping the black powder that forms when reducing copper salts with steel (though it should be washed with acid to remove the black copper oxide), pyrolyzing sugar, etc.

Glassy carbon can be bought online as electrodes.

Preparation

Charcoal that has been crushed and leached with boiling water, or coke prepared in a similar way are sufficient for most uses of carbon.

Amorphous carbon can be made by dehydrating sugar with sulfuric acid. Once it has been washed of excess acid, this is a very pure form of carbon.

Diamond powder can be made by passing electrical current through graphite for a long period of time. Larger diamonds cannot be feasibly made in a nonindustrial setting.

Buckyballs are present in soot, though the percentage is insignificant. Commercially, they are prepared by extraction of the pyrolysis products of aromatic compounds, or by an arc discharge between two graphite electrodes.

Projects

Handling

Safety

Pure carbon has extremely low toxicity to humans and can be handled and even ingested safely in the form of graphite or charcoal, and USP charcoal is used for treating various medical conditions.

Inhalation of coal dust or soot (carbon black) in large quantities, however, can be dangerous, as it irritates lung tissues and causes various congestive lung diseases. Powdered diamond is highly abrasive, and proper protection must be worn when working with it.

Storage

No carbon allotrope requires any special storage. Amorphous carbon, however, if it has high specific surface area, may adsorb gasses from the air, such as volatile organic compounds (VOC) or acidic vapors which will lower the purity of the carbon. It is best stored in tightly sealed containers.

Disposal

Amorphous carbon can burn in an oxidizing atmosphere, but the other carbon allotropes burn only at high temperatures. Carbon traces from various glassware can be cleaned either with aqua regia or piranha solution. No common carbon allotrope poses any threat to the environment, so no special disposal is required when discarding carbon waste and may be dumped in trash. Used industrial graphite electrodes may be contaminated with heavy metals and should be taken to disposal centers.

References

  1. ↑ https://www.youtube.com/watch?v=g3ar6zGcTQY

Relevant Sciencemadness threads

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