Silicon Dioxide, SiO2, (which is also known as Silica) is
widely distributed in the environment, and is present in
the form of sand on all beaches.
Preparation of Silicon Dioxide
Silica is prepared by the hydrolysis of silicon tetrachloride
with water and heating the hydrated oxide formed.
SiCl4 + 4 H2O ==> SiO2.2 H2O + 4 HCl
Properties of Silicon Dioxide
Silica is a transparent solid with high melting point.
Silica is inert to most chemical reagents but reacts with
hydrogen fluoride to form silicon tetrafluoride, which is
a colourless gas at room temperature and water.
Silica is an acidic oxide, which reacts with alkalis to
form salt and water.
SiO2 + 2NaOH ==> Na2SiO3 + H2O
Properties of Silicon Dioxide
Silicon dioxide is a crystalline compound that transmits
visible and ultraviolet light. Many crystalline forms
exist, the most common of which is Quartz.
Uses of Silicon Dioxide
Ultra pure silicon dioxide is an important materials in
the electronics industry.
When silica is mixed with solid sodium carbonate and melted,
sodium silicate is formed. This reaction is the basic
reaction in the manufacture of glass.
SiO2 + Na2CO3 ==> Na2SiO3 + CO2
Cement is a complex aluminum silicate. Its strength is
due to the strong bonding of the SiO4 groups.
Start of Hypertext ....
Elements ....
Compounds ....
Index
Hypertext Copyright (c) 2000 Donal O'Leary. All Rights Reserved.