Wednesday, January 24, 2018

everyday chemistry - Physical state of the carbon denoted with "gr"



I would like to know what does a gr mean when used to represent the physical state of the carbon, for example, in the synthesis of the glucose


6CX(gr)+6HX2X(g)+3OX2X(g)CX6HX12OX6X(),


what does the gr mean?



Answer



The letters in brackets indicate state of aggregation (includes state of matter, crystal structure (solids) and atomicity (gases)), therefore CX(gr) most likely refers to graphite. Often one can also see C(s,gr) or C(s,graphite) There is a nice demonstration in [1, p. 248]:



C(gr)+OX2(g)COX2(g) Here (g) indicates that the compound is gas, [...], and (gr) that carbon is graphite (not many people will burn diamonds, even if they are chemists).



P. S. According to IUPAC recommendations, subscript notation is deprecated.




  1. Metiu, H. Physical Chemistry: Thermodynamics; Garland Science, 2006. ISBN 978-1-315-31491-4.


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