Question 3
In activity 16.1 (i), what is the white powder that forms on the inner face of the covering spoon?
The right answer is the one marked above.
Solid camphor, formed by vapour condensing on a cool surface. It is not a new substance but camphor itself — which is why this is a physical change.
Had a new compound formed, this would be a chemical change. The proof that none did is that heating the powder turns it straight back into vapour.