Question

Graphite is used as a lubricant in machines because it has a very high melting point and also it :

• A. is crystalline
• B. has layer structure
• C. is a giant molecule
• D. is a liquid at room temperature

Answer 1

The correct option is B has layer structure

Graphite has a layered structure of hexagonal rings. It has one carbon atom 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.