Question

In which of the following reaction “Philosopher’s wool” is formed:
(a)- $Zn+S\xrightarrow{\Delta }ZnS$
(b)- $Zn+C{{l}_{2}}\xrightarrow{\Delta }ZnC{{l}_{2}}$
(c)- $FeS+{{O}_{2}}\xrightarrow{\Delta }FeO+S{{O}_{2}}$
(d)- $Zn+{{H}_{2}}O(steam)\xrightarrow{\Delta }ZnO+{{H}_{2}}$

Answer 1

Hint: Philosopher's wool is an oxide of an element that belongs to the d-block. The other names of Philosopher's wool are calamine, Chinese white, the flower of zinc.

Complete step by step answer:
Philosopher wool is the oxide of zinc. Hence, it is zinc oxide which has a formula $ZnO$ It is obtained by the reaction:
 $Zn+{{H}_{2}}O(steam)\xrightarrow{\Delta }ZnO+{{H}_{2}}$

It is a white powder. It is insoluble in water. The molecular mass of zinc oxide is $81.406\text{ g/mol}$. It is an odorless compound.
It is used to make products like rubbers, plastics, batteries, filaments, paints, ointments, adhesives, first-aid tapes, food supplements, fire retardants, glass, cosmetics, etc.
It is used in LCDs (liquid crystal displays), light-emitting diodes, thin-film transistors, etc because it has good transparency, high electron mobility, wide bandgap, and strong room-temperature luminescence.
It is called Philosopher's wool because in ancient times the Alchemists used to burn zinc in the air as a part of their rituals and then they collect the residue, which is then converted into white wooly tufts. In Latin, it is called Lana philosophica, which means Philosopher’s wool.
In nature, the zinc oxide occurs as a rare mineral zincite, which usually contains manganese and other impurities that confer a yellow to red color.
Zinc oxide dissolves in most of the acid. When it is treated with hydrochloric acid it forms zinc chloride. The reaction is: $ZnO+HCl\to ZnC{{l}_{2}}+{{H}_{2}}O$

So, the correct answer is “Option D”.

Note: The zinc oxide has a wide variety of applications, this is because of its properties like high refractive index, UV-protection properties, binding, antibacterial, and high thermal conductivity. It is mostly used in rubber manufacture, around 50-60%.