The Solid State

Question 73
CBSEENCH12005421

What are non-stoichiometric compounds?

Solution
Non-stoichiometric compounds are chemical compounds, almost always solid inorganic compounds, having elemental composition whose proportions cannot be represented by integers; most often, in such materials, some small percentage of atoms are missing or too many atoms are packed into an otherwise perfect lattice work. exaple FeO, ZnO etc.
Question 74
CBSEENCH12005422

In which compound  Schottky and Frenkel defects are present together?

Solution
Silver bromide (AgBr) has both Schottky and Frenkel defects together.
Question 75
CBSEENCH12005423

What is the percentage of free space in a body centred cubic crystal?

Solution
In body centred cubic crystal packing effciency is 68% thus free space in body centred cubic crystal is free space effciency = 100- 68%
                              = 32%
Question 76
CBSEENCH12005424

Give one example of anti ferroelectric solid and one example of ferroelectric solid.

Solution
Antiferro electric solid-PbZrO3 (Lead Zirconate).
Ferro electric solid-BaTiO3 (Barium Titanate).

NCERT Book Store

NCERT Sample Papers

Entrance Exams Preparation