Question

Graphite is a soft lubricant extremely which is difficult to melt. What is the reason for this anomalous behaviour?

• A. Strong covalent bonds in the sheet-like structure but weak force between the layers.
• B. Strong covalent bonds in the sheet-like structure and strong force between the layers.
• C. Weak covalent bonds in the sheet-like structure and weak force between the layers.
• D. Weak covalent bonds in the sheet-like structure but strong force between the layers.

Answer 1

The correct option is A Strong covalent bonds in the sheet-like structure but weak force between the layers.

Graphite is an extremely soft lubricant but is difficult to melt. The reason for this anomalous behaviour is that graphite has carbon atoms which are covalently bonded with three other carbon atoms which are arranged in a sheet-like structure stacked over one another. The bonds within the sheet are strong but between the layer is weak. The weak force between the layers makes it a good lubricant but the strong force in the sheet makes it hard to melt.