Grade 1010 grade science

Chemical bonding in graphite. How valency of graphite is satisfied in graphite

Seema

8 Years agoGrade 10

2 Answers

Arun

8 Years ago

Dear Seema

Carbon can bond with one (CO),two (CO2) ,three(graphite) or four other (CH4) atoms.

In graphite it is only bonding with other carbons. In graphite the bonds are made on a flat plane and since the shell requirements of the carbons are fulfilled, the layers of carbon are not attracted to each other. That is wht graphite is a dry lubricant because of it only bonding with three carbons. If it bonded with four carbons, you would have a different geometry and it would be a lot less mobile. In fact a four carbon bond with each other makes diamond.

Look at this picture of graphite and see how the layers of carbon are not influenced by each other. It is that planar structure that fulfills the valency of the carbon but allows the sheets of carbon to slide between each other. The graphite is actually the individual flat sheets

https://en.m.wikipedia.org/wiki/File:Graphite-layers-side-3D-balls.png

Regards

Arun

SR Roy

8 Years ago

In the hexagonal graphite structure the carbon atoms are sp2

hybridized, just like in benzene. In graphite, this p-orbital is used for bonding just as it is in benzene, resulting in an extended pi system in the graphite structure. Graphite is really just a large number of benzene rings annelated together to form a continuous, ring structure. Just as carbon satisfies its valence requirement of 4 in benzene (3 sigma bonds and 1 pi bond), carbon's valency requirements are satisfied the same way in graphite.