Silicon carbide, SiC, has a very high melting point and a structure like that of diamond.
(a) Silicon carbide is made by heating carbon with silicon dioxide, SiO2, at high temperature. The other product of the reaction is carbon monoxide, CO.
Construct a balanced equation for the reaction.
i) Draw a diagram to show the possible structure of silicon carbide. Use this structure to suggest why silicon carbide has a very high melting point.
ii) Suggest two other physical properties of silicon carbide.
Photo is obtained from http://en.wikipedia.org/wiki/File:SiC_p1390066.jpg
(b) i) Diagram of silicon carbide possible structure
The structure is in a tetrahedral shape, which is a macromolecular compound. Macromolecular compound has high melting point.
ii) They are very hard and do not conduct electricity.
- CHEMISTRY Matters (G.C.E. ‘O’ Level), 3rd Impression (2008), by Tan Yin Toon, Chen Ling Kwong, John Sadler, Emily, Published by Marshall Cavendish Education, Printed in Singapore by Times Printers, www.timesprinters.com, Chapter 7 - “Covalent and Metallic Bonding”, Page 110