Carbon is available in pure form as coal, graphite and diamond.
Graphite is also very stable and resistant to damage by environmental exposure.
Like diamond it has high melting point.
It finds many uses in daily life due to its properties.
Properties of Graphite
1. Layer structure of graphite
2. High melting point
4. Slippery / lubricant
5. Electrical conductivity
Layers: Graphite is arranged in layers. These layer slide over each other with ease. These layers facilitate electrical conduction. It was also believed that the lubricant property of graphite was also due to these layers.
High melting point: Graphite has high melting point. Its melting point is 4026° C and unlike other elements it does not convert to liquid form from the solid state. Instead it converts to gaseous form directly from solid state. A type of sublimation process.
Luster: Graphite like metal is shiny in appearance. It has earth like color and is metallic in touch. Due to this luster, it is used in paints.
Slippery: Graphite is quite slippery in touch. This gives it a lubricant feel. This lubricant property is due to super-lubricity.
Electrical conductivity: Graphite is good conductor of electricity. The delocalised electrons in graphite help in electrical conduction. Hence, the pencil nib should not be put inside a switch as it can lead to electrical shock. Since, children use the pencils for study, they should be cautioned.
Solubility: Graphite is not water soluble and other organic solvents.
Density: The density of graphite is lower that that of diamond due to large spaces between layers sheets.
Applications of graphite in daily life:
- As pencils for writing. Here graphite is used as a mix of pure graphite and clay.
- As electrodes for conduction especially in batteries.
- In paints and other colors
- In steel making.