CBSE Class 12th Chemistry Chapter1 The Solid State -Part20

Class XII Chemistry Chapter 1 The Solid State NCERT Solution is given below.

Question 1.19:
What type of defect can arise when a solid is heated? Which physical property is affected by it and in what way?
Answer
When a solid is heated, vacancy defect can arise. A solid crystal is said to have vacancy defect when some of the lattice sites are vacant.
Vacancy defect leads to a decrease in the density of the solid.

Question 1.20:
What type of stoichiometric defect is shown by:
(i) ZnS (ii) AgBr
Answer
(i) ZnS shows Frenkel defect.
(ii) AgBr shows Frenkel defect as well as Schottky defect.