Question

A zinc salt, E when

Answer 1

Answer:

The salt is Zn(NO3)2

When the residue is allowed to cool, its colour changes from yellow to white

The equation of the reaction is; 2Zn(NO3)2(s) --->2ZnO(s) + 4NO2(g) + O2(g)

Explanation:

Decomposition of Zn(NO3)2 is one of the routes by which ZnO is obtained. ZnO is a white insoluble powder which has a yellow colour when hot and a white colour when cold. It is an amphoteric substance used as a white pigment in paints and as a filler for rubber.

In a very pure form, it is used in cosmetic powders and creams as well as in medicinal ointments and lotions.

Also recall that NO2 is a brown gas and oxygen gas rekindles a glowing splint.