Question

Which of the following is/are the constituent (s) of glass?
A.Silica (sand)
B.Calcium carbonate (limestone)
C.Sodium carbonate
D.All of the above

Answer 1

Hint: Glass is basically one of the versatile and oldest human-created tools by man. It is manufactured from opaque sand but is completely transparent. Moreover, it is a transparent solid substance and non-crystalline amorphous in nature.

Complete step by step answer:
-Glass is a transparent solid substance. It is non-crystalline in nature. Scientifically, every solid with a non-crystalline structure which exhibits a glass transition when heated towards the liquid state is called Glass.
-Now, in conventional methods, the sand is heated to extreme temperature and allowed to cool down and then shaped into any form by either blowing or pouring into pre-designed moulds. This is an easy process because additives can be added to improve the quality of glass and enhance its appearance with different colors. The various constituents of glass are listed below:
Silica- It is the principal constituent of glass. If silica alone is used in the manufacture of glass then it could be fused only at a very high temperature. But it is imperative to add sodium or potassium carbonate or lime in suitable proportions to make the molten silica glass sufficiently viscous.
Sodium or potassium carbonate- It is an alkaline material and forms an essential component of glass. Moreover, it is added in suitable proportion to reduce the melting point of silica.
Lime- It basically imparts durability to the glass. Moreover it is added in the form of chalk.
Coloring substances- Various coloring substances such as cuprous oxide, manganese dioxide, tin oxide, and chromic oxide can be added to impart color to glass.
Therefore, silica, calcium carbonate, sodium carbonate all are constituents of glass.

Hence, option D is correct.

Note:
The glassware used in the kitchen are generally made of borosil or Pyrex glass. This is because it does not crack on heating or cooling because of its low coefficient of expansion. Further, these kinds of glass are very thin and hence, the inner and outer surfaces expand equally.