Question

Graphite is a soft solid lubricant extremly difficult to melt. The reason for this anomalous behaviour is that graphite :

• A. has carbon atoms arranged in large plates of rings bonds
• B. is a non-crystalline substance
• C. is an allotropic form of carbon
• D. has molecules of variable molecular masses like polymers

Answer 1

The correct option is A has carbon atoms arranged in large plates of rings bonds

Graphite has a layered structure of hexagonal rings. It has carbon atoms covalently bonded to three other carbon atoms, forming a giant hexagonal molecular structure with layers held by weak Van der Waals' forces. As the Van der Waals' forces between the layers are weak, the layers can easily slide over each other when pressured and is soft. Thus, it can be used as a lubricant.