Question

Philosopher's wool on heating with $BaO$ at $110^oC$ gives:
A. $BaCd\mathop O\nolimits_2$
B. $Ba + Zn\mathop O\nolimits_2$
C. $Ba\mathop O\nolimits_2 + Zn$
D. $BaZnO_2$

Answer 1

Zinc oxide is also called philosopher's wool. When Philosopher's wool (or Zinc oxide) is heated with the Barium Oxide at the temperature around 1100 °C it produces the Barium Zincate.

Complete step by step answer:
In this question we have asked, what will form when philosopher wool reacts with $BaO$ at $110^oC$. So, first of all, what is philosopher wool? The compound zinc oxide ($ZnO$ ) is called philosopher’s wool. Alchemists, as part of their rituals, would burn zinc in air and collect the soluble residue, which formed into white woolly tufts. They called it lana philoshophica in Latin, meaning philosopher's wool.
When Philosopher’s wool (i.e. $ZnO$ is heated with $[BaO$ at $1100^oC$, it gives $BaO + ZnO \to BaZnO_2$ .
In $BaZn\mathop O\nolimits_2$, the Zn and O ions are arranged in a distorted high (fl-) quartz structure, while the Ba ions fill up the widened holes between the O tetrahedra. Our first option is $BaCd\mathop O\nolimits_2$ which is absolutely wrong as no Cd is present in the reactants. Option B. is $Ba + Zn\mathop O\nolimits_2$, which is also wrong. The 3rd option is $Ba\mathop O\nolimits_2 + Zn$ which is also wrong.
So, the correct option is D i.e $BaZnO_2$

Note:
Zinc oxide has many uses: as white pigment in paints, component in zinc ointment for treating skin diseases, material in sunscreens and sun lotions, in rubber manufacture and in photocopying products.