Graphite Structure, Characteristics: 31 Complete Quick Facts


In this article, “graphite structure” different properties like structural properties, characteristics, uses with some relevant topics are discussed below.

Graphite is also known as plumbago or black lead and it is a mineral consisting of carbon. It has a two dimensional layered structure having rings of six carbon atoms. Graphite crystallizes in hexagonal systems. It is relatively soft and black grey in colour.

Let’s focus on the following topics related to the structure of graphite.

What is structure of Graphite?

Graphite is basically one of the most stable allotropes of carbon. It is a good conductor of electricity and heat having the density 2.09-2.23 g/cm3 with a great covalent structure in which each carbon atom is joined with neighboring three carbon atoms.

In graphite each of the carbon atom is sp2hybridized which forms a layer like structure with the arrangement of hexagonal arrangement of carbon atoms. These layers are weakly bonded with each other. Due to presence of the weak force between the layers, they slip over very easily.

Carbon has four valence electrons and one carbon atom is bonded with another three carbon atoms, thus, one valence electrons are left and this valence electron is delocalized in the structure.

graphite structure
Graphite structure.
Image credit: Wikimedia Commons.

How to draw Graphite lewis structure?

To know the lewis structure of any molecule, first the constituent atoms of that molecules should be determined first. The actual lewis structure of graphite is very much complex due to having layered structure.

Graphite is made with only carbon atom in which one carbon atom is bonded with another three carbon atoms. So, one among the four valance electrons is left as nonbonding electron pair. Total 3*2=6 electrons are from each of the carbon atom are involved in bonding electron pairs.

Lewis structure of graphite

Graphite Lewis Structure Formal Charge

  To know the formal charge of any molecule, determination of the structure is very much mandatory. But the structure of graphite is very much complex as it has the layered structure. Thus, to simplify the determination of lewis structure we have selected only one fragment from graphite containing three carbon atoms.

  • Formal charge = Total number of valance electrons – number of electrons remain as nonbonded – (number of electrons involved in bond formation/2)
  • Formal charge of the central carbon atom = 4 – 1 – (4/2) = 1

Thus, one electron is left as nonbonding electrons and it becomes delocalized over the structure.

Graphite Lewis Structure Angle

The angle indicates basically the angle between two bonds connecting by the central atom. The bond angle depends upon the hybridization of the central atom of any molecule more over the repulsion factors present in that particular molecule.

These repulsion factors are –

  • Lone pair-lone pair repulsion
  • Lone pair- bond pair repulsion
  • Bond pair-bond pair repulsion.

The hybridization is the main factor to determine the bond angle.

Hybridization of central atom   Bond angle
sp1800
sp21200
sp3109.50
sp3d2900

In graphite, one s and two p orbitals are involved in sp2hybridization. From the above table it is shown that the bond angle will be 1200 and the bond lengths are 1.421 A0.

Graphite Lewis Structure Octet Rule

Octet rule is one of the most important rule in inorganic chemistry in which it is stated that any atom should have such electron configuration which resembles with the electron configuration of nearest noble gas in periodic table.

In one point of view graphite does not obey octet rule. Thus, it should not be stable. But the experimentally it is shown that stability of graphite is very much high. Because the extra or the nonbonded electron in the graphite structure is delocalized over all the carbon atoms.

Therefore, graphite is stable though it does not satisfy octet rule.

We basically represent the delocalized electron as the double bond and write the structure with alternative double bond. But as this double bond rotated, all the bond lengths become equal.

Graphite Lewis Structure Lone Pairs

Graphite has no lone pair of electrons. Lone pairs are those type of valence electrons which are not involved in any bond formation.

Carbon has total four electrons in its outer most shell. Among the four electrons, three electrons are involved in three sigma bond formation. The electron, which is left cannot be counted as lone pairs or nonbonded electrons because this electron form pi bond with the other carbon atom. This pi bond or the left electron is delocalized over the whole structure and helps graphite to conduct heat and electricity.

Graphite Solubility

Graphite is one of the best source of carbon but it is insoluble in most of the organic and inorganic solvents. If we sonicate graphite for a long time, then it can be soluble dispersed in some organic solvents with proper amount of additives.

But this process (long time sonication) creates defects and cracks in the structure of graphite. Besides that, graphite in solid state is not soluble in most of the polar or non-polar solvents. But it may soluble in molten Nickel and chlorosulphuric acid. Solid graphite can be suspended by some emulsifier in oil or in water.

Is Graphite a strong electrolyte?

Strong electrolytes can be defined as those substance who can be dissociated into its constituent ions after dissolving in water.

Graphite cannot be dissolved in water due to its structure. Thus, it can’t be an electrolyte because it can’t be separated into ions. But it can conduct electricity due to the lone electrons which are delocalized over the whole graphite structure.

Is Graphite acidic or basic?

If the graphite is treated with strong oxidizers and acids, graphite oxide can be obtained as the product which was formerly known as graphitic oxide or graphitic acid.

In the structure of graphite oxide, the ratio between carbon with oxygen lies between 2.1 and 2.9. In this compound, the layered structure of graphite is retained but with a much larger and irregular spacing. It shows the acidic property.

Is Graphite polar or nonpolar?

Polarity of any molecular structure depends upon the following two factors-

  1. Electronegativity difference between the atoms
  2. Orientation of the bonds.

Graphite is made with only carbon atoms. Thus, electronegativity of all the constituent atoms are equal and no electronegativity difference is observed in graphite structure.

For this reason, graphite does not show any dipole moment. So, it is a nonpolar molecule.

Is graphite magnetic?

Graphite is not a magnetic component. Magnetic component can be categorised into the following sections-

  • Paramagnetic
  • Diamagnetic
  • Ferromagnetic
  • Ferrimagnetic

Each carbon atom six electrons (1s22s22p2). Three of these six electrons exhibit an upward spin direction and another six electrons exhibit a downward spin direction which are cancelled by the upward spin direction. Thus it does not show any magnetism and is repelled by the external magnetic field. 

But if graphene is twisted or stacked, a rare form of magnetism can be developed.

Is graphite metallic or nonmetallic?

Graphite is one of the allotropes of carbon. Thus, it is a nonmetallic substance. It has a covalently bonded layered structure.

But one of the most important characteristics of metal is to conduct electricity and heat. Graphite can also conduct heat and electricity because of the delocalized electron. The main difference with metal is that free electrons are also present in metals and they are delocalized through all over the structure. But the free electrons from one layer are delocalized over the one layer of graphite structure not in the another layer.

Is graphite brittle?

Graphite is naturally a very much brittle compound due to its structure.

In graphite, one carbon atom is bonded with another three carbon atoms by three covalent bonds in a two-dimensional ‘layer lattice’. Individual layers are strong due to presence of three strong covalent bonds, but the layers in graphite can be separated by applying slightest disturbance because the layers are connected with each other by the weak Van der Waals force.

Thus, graphite is a soft and brittle substance.

Is graphite crystalline or amorphous?

Graphite is a crystalline allotrope of carbon like diamond.

Crystalline compounds are those in which many atoms (more than 1000 atoms) are bonded in a repeating pattern. In graphite also a particular structural pattern is followed. One layer lies over another layer and attached with weal van der waals force.  In one fragment of graphite, one carbon is attached with its neighbouring three carbon atoms by three strong covalent bonds.

Is graphite lighter than steel?

Graphite shafts are much lighter than steel and more expensive also. Shafts that are made with steel is heavier than graphite.

One of the main reason of steel being heavy is that it is an alloy of carbon and iron. Thus, one metal substance is present in steel. But graphite is only the allotrope of carbon. Thus, it is lighter than steel due to absence of any metallic substance.

Is graphite radioactive?

Normal graphite is very much less radioactive. Because for one gram of carbon there is one pico gram (10-12) amount of carbon is radio active (carbon-14). This 14C is radio active because it emits beta rays to become 14N.

Graphite uses

Graphite has different uses in industry like-

  • Writing materials – Pencils are made of graphite.
  • As lubricants
  • Refractory
  • Nuclear reactors
  • Batteries
  • Graphene sheets
  • Foundry facings
  • Brake linings

Conclusion

Graphite contains with a layered structure and is one of the most stable allotropes of carbon. This non-metallic substance can conduct electricity due to its free delocalized electrons. It is a soft and brittle compound with lots of uses in industry.

Aditi Roy

Hi..I am Aditi Roy, I have completed my graduation from University of Calcutta and am pursuing M.Sc in Chemistry from Techno India University. My area of specialization is on Inorganic Chemistry.

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