| MadSci Network: Chemistry |
When using chemical symbols, how is diamond differentiated from graphite?
I know that both diamond and graphite are allotropes of carbon,
but all I can find is information on the difference in structure.
Normally, phase differences or allotropic differences are represented by subscript words or abbreviations in parentheses. For example, when you mix a solution of barium nitrate with a solution of copper sulfate, you obtain a precipitate of barium sulfate. This is represented thus:
Ba(NO3)2(aq) + CuSO4(aq) ® Cu(NO3)2(aq) + BaSO4(s)
In this case, (aq) means a species in aqueous solution and (s) means a solid (or precipitated, sometimes represented by "ppt") material.In the same way, if you wanted to represent diamond or graphite specifically you could write either C(diamond) or C(graphite).
There are special cases in which allotropes have different molecular formulae. For example, ozone (O3) and molecular oxygen (O2) are allotropes; so are white phosphorus (P4) and polymeric red phosphorus (Pn). For carbon, there are various molecular fullerene allotropes such as C60 and C70. In such cases, giving the correct molecular formula is sufficient.
| Dan Berger | |
| Bluffton College | |
| http://cs.bluffton.edu/ ~berger |
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