Question

Graphite is soft solid lubricant extremely difficult to melt. The reason for this anomalous behavior is that graphite:

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

Answer 1

The correct option is B has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interpolate bonds

In graphite, carbon is $s{p}^2$ hybridized and each carbon is thus linked to three other carbon atoms forming hexagonal rings. Since only three electrons of each carbon are used in making a hexagonal ring, the fourth electron of each carbon is free to move and is thus delocalized ober the ring. This makes graphite good conductors of electricity.

Also, graphite has a two-dimensional shell-like structure. Such sheets are held together by weak van der Waals forces; it is because of these weak forces of attraction, one layer can slip over the other thus graphite acts as an exceptional lubricant.