CBSE Class 12th Chemistry Chapter 1 The Solid State -Part1

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

Question 1.1:
Define the term ‘amorphous’. Give a few examples of amorphous solids.
Answer
Amorphous solids are the solids whose constituent particles are of irregular shapes and have short range order. These solids are isotropic in nature and melt over a range of temperature. Therefore, amorphous solids are sometimes called pseudo solids or super cooled liquids. They do not have definite heat of fusion. When cut with a sharp-edged tool, they cut into two pieces with irregular surfaces. Examples of amorphous solid include glass, rubber, and plastic.

Question 1.2:
What makes a glass different from a solid such as quartz? Under what conditions could quartz be converted into glass?
Answer
The arrangement of the constituent particles makes glass different from quartz. In glass, the constituent particles have short range order, but in quartz, the constituent particles have both long range and short range orders.
Quartz can be converted into glass by heating and then cooling it rapidly.