Question

Explain the lubricating property of graphite on the basis of its structure.

Answer 1

1. Graphite has a layered structure in which each carbon atom is covalently bonded to three other carbon atoms, forming hexagonal rings in flat two-dimensional sheets.
   1. These layers are held together by weak van der Waals forces, not strong covalent bonds.
   2. Because of these weak forces, the layers can easily slide over one another when pressure is applied.
2. This easy movement of layers makes graphite soft and slippery, which is why it acts as an effective solid lubricant, especially in machines working at high temperatures where liquid lubricants fail.