Some Important Compounds Of Carbon And Silicon
Chapter Name : The P- Block Elements |
Sub Topic Code : 102_11_11_09_03 |
Topic Name : Some Important Compounds Of Carbon And Silicon |
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Sub Topic Name : Silicon Dioxide |
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Introduction
1.95% of the earth’s crust is made up of silica and silicates. 2.Silicon dioxide, commonly known as silica, occurs in several crystals. 3.Quartz, cristobalite and tridymite are some of the crystalline forms of silica. 4.Silicon dioxide is a covalent, three-dimensional network solid in which each silicon atom is covalently bonded in a tetrahedral manner to four oxygen atoms. 5.Each corner is shared with another tetrahedron. 6.The entire crystal may be considered as giant molecule in which eight membered rings are formed with alternate silicon and oxygen atoms. 7.Silica in its normal form is almost nonreactive because of very high Si—O bond enthalpy. 8.It resists the attack by halogens, Di-hydrogen and most of the acids and metals even at elevated temperatures. 9.However, it is attacked by HF and NaOH. 10.Quartz is extensively used as a piezoelectric material; it has made possible to develop extremely accurate clocks, modern radio and television broadcasting and mobile radio communications. 11.Silica gel is used as a drying agent and as a support for chromatographic materials and catalysts. 12.Kieselghur, an amorphous form of silica is used in filtration plants.
Pre-Requisites:
Elements, periodic table
Activity:
Notice how the silica gel sachets are kept in new merchandise such as bags and containers. These are used to remove moisture
Real Life Question:
What is silica gel used for?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| P block elements | Have the last electron in the outermost p orbital |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Silica gel sachets | Notice how the silica gel sachets are kept in new merchandise such as bags and containers.. These are used to remove moisture |
| watches | Quartz in watches is an efficient piezoelectric material |
Real life uses :
1.Silica is used as a drying agent. 2.A different form of silica called as keiselghur is used in filtration plants.
Places to visit :
Kitchen
Practical examples around us
| Examples | Explainations |
|---|---|
| Silica gel sachets | Notice how the silica gel sachets are kept in new merchandise such as bags and containers.. These are used to remove moisture |
What you learn in Theory:
1.95% of the earth’s crust is made up of silica and silicates. 2.Silicon dioxide, commonly known as silica, occurs in several crystals. 3.Quartz, cristobalite and tridymite are some of the crystalline forms of silica. 4.Silicon dioxide is a covalent, three-dimensional network solid in which each silicon atom is covalently bonded in a tetrahedral manner to four oxygen atoms. 5.Each corner is shared with another tetrahedron. 6.The entire crystal may be considered as giant molecule in which eight membered rings are formed with alternate silicon and oxygen atoms. 7.Silica in its normal form is almost nonreactive because of very high Si—O bond enthalpy. 8.It resists the attack by halogens, Di-hydrogen and most of the acids and metals even at elevated temperatures. 9.However, it is attacked by HF and NaOH. 10.Quartz is extensively used as a piezoelectric material; it has made possible to develop extremely accurate clocks, modern radio and television broadcasting and mobile radio communications. 11.Silica gel is used as a drying agent and as a support for chromatographic materials and catalysts. 12.Kieselghur, an amorphous form of silica is used in filtration plants.
What you learn in Practice:
Quartz is an efficient piezoelectric material