Question

Which material would be totally involatile?

`"i. camphor;"`
`"ii. graphite;"`
`"iii. ammonium chloride;"`
`"iv. iodine?"`

Answer 1

`"Graphite is the only contender.........."`

Explanation:

Graphite is the only material that is NON-MOLECULAR; camphor, and iodine are molecular. Ammonium chloride is a salt, that could be decomposed with heating to give `NH_3(g)` and `HCl(g)`, but this would recombine as the salt on cooling.

On the other hand, graphite is composed of an infinite array of carbon-carbon bonds in two dimensions, and as a result has highly elevated melting and boiling points. Graphite is thus non-volatile, and non-sublimable.