Describe different types of glass briefly.

ANS:



Soda Glass (Soft Glass) :



Soda glass is the ordinary glass also called soft glass.

It is made by melting soda ash, sand and quick lime.

It is used for making glass tumblers, dishes, bottles, mirrors, window panes, light bulbs, etc.



Potash Glass (Hard Glass) :



Hard glass is prepared by melting a mixture of potassium carbonate, calcium carbonate and silica.

It is more resistant to acids.

It is used for making hard glass laboratory apparatus.



Lead Crystal Glass :



Lead crystal glass is made by melting potassium carbonate, lead oxide and silica.

It is used for making costly glass apparatus and for producing flashes by reflection of light.



Pyrex Glass (Heat Resistant Glass) :



Pyrex glass is made by melting a mixture of sand, quick lime, borax and alkali carbonate.

It is also known as Borosilicate glass.

It is used for making ampoules and laboratory apparatus.[An ampoule is used to store liquid medicines, usually for injections.]



Optical Glass :It is used for making lenses for spectacles, cameras, microscopes, telescopes and similar optical instruments.

Photochromatic Glass :



Photochromatic glass is the one which darkens temporarily when exposed to bright light.

Silver bromide in the glass gives it its property of automatic darkening.

It is used for making spectacles to protect eyes from sun's heat(sunglass).



Safety Glass :



It is prepared by placing a thin sheet of transparent plastic between two layers of glass.

It is safe as it does not break easily.

It is used for making the windscreens of automobiles, trains and aeroplanes.

It is also used in making bullet-proof glass.



Glass Fibre :



It is heat resistant.

It is used in refrigerators, ovens, etc.

Optical fibres are used in telecommunication because their efficiency is more than copper cables.

Optical fibres are also used in endoscopy to examine the internal organs of human body.



Coloured Glass :



Coloured glass is obtained by adding small amounts of colouring material like certain metal oxides in molten state during preparation of glass.

For example, Ferric oxide for brown glass, chromium oxide for green glass, manganese dioxide for purple(violet) glass and cobalt oxide for blue glass.

Coloured glass is used for making fancy articles, artificial gems and window panes.