Question

Graphite is a soft lubricant but is extremely difficult to melt. The reason for this anomalous behaviour is the ______ bonds within its sheet like structure and ______ force between the layers.

• A. strong, weak
• B. strong, strong
• C. weak, weak
• D. weak, strong

Answer 1

The correct option is A strong, weak

$\bullet$ Graphite has carbon atoms which are covalently bonded with three other carbon atoms.
$\bullet$ These are linked in hexagonal arrangement forming 2D sheets stacked over one another.
$\bullet$ The covalent bonds within the layer are strong but the layers are held by weak van der Waals forces.
$\bullet$The weak force between the layers makes it a good lubricant but the strong bonds within the sheet makes it hard to melt.