Glass

GLASS

Name of the Substance: Glass

Chemical name of Substance: Any non-crystalline (amorphous) solid, Super cooled                                                   liquid.

Chemical Composition: It is compound silica (silicon dioxide, or quartz), the primary                                       constituent of sand. Soda-lime glass, containing around 70%                                       silica, account for around 90% of manufactured glass.

Chemical             composition,                            wt%

74 SiO2, 13 Na2O, 10.5 CaO, 1.3 Al2O3, 0.3 K2O, 0.2 SO3, 0.2 MgO, 0.01 TiO2, 0.04 Fe2O3

                          

Chemical Structure: On cooling molten silica quickly, a random organised network                        of these tetrahedra are formed, linked at their corners, to give an                        amorphous material known as vitreous silica.

           

                                  

 Physical Properties:

1.     Optical glass typically has a refractive index of 1.4 to 2.4

2.     It has ability to refract, reflect, and transmit light following geometrical optics.

3.     Glass transparency results from the absence of grain boundaries which diffusely scatter light in polycrystalline materials.

4.     The density of glass varies with chemical composition with values ranging from 2.2 grams per cubic centimetre (2,200 kg/m³) for fused silica to 7.2 grams per cubic centimetre (7,200 kg/m³) for dense flint glass.

5.     It is most viscous solid.

Reactivity

1.     Glass is typically inert, resistant to chemical attack, and can mostly withstand the action of water

2.     Glass will corrode or dissolve under some conditions. The materials that make up a particular glass composition have an effect on how quickly the glass corrodes. Glasses containing a high proportion of alkali or alkaline earth elements are more susceptible to corrosion than other glass compositions.

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 Uses:

1.     It has widespread practical, technological, and decorative use in, for example, window panes, tableware, and opticsGlass has been traditionally used for vessels: bowls, vases, bottles, jars and drinking glasses.

2.     It has also been used for paperweights and marbles.

3.     Glass can be colored by adding metal salts or painted and printed with vitreous enamels, leading to its use in stained glass windows and other glass art objects.