Silicon

 

Silicon

Chemical formula	Si
Atomic Number	14
OTP appearance	black solid
Molar Mass(g/mol)	28.0
Melting Point(°C)	1414
Boiling Point(°C)	3265
Density(g/cc)	2.33
NFPA 704	0 1 0

Uses

Justifying

• -dioxide is the key component of glass

Other

• Semiconductor substrate
• Feedstock for silicone
• -carbide is an excellent abrasive, high temp ceramic, semiconductor "detector"
• -dioxide accepts CaO (SiO₂ + CaO → CaSiO₃)

Natural Occurrence

• Elemental silicon does not occur naturally
• silicon dioxide occurs as the minerals quartz (and flint, chert, sand, etc.)

Production

Extraction

• from dioxide via high temp (1900°C) carbothermal reduction

  SiO₂ + 2 C → Si + 2 CO

• from -fluoride with potassium via halide stealing

  SiCl + K → Si + KCl

via silicides

In an article

1. Combine finely ground sand, [[quartz], or quartzite with magnesium metal powder, and heat, yielding magnesium silicide, magnesium oxide, and unreacted magnesium and silicon dioxide

   2 Mg + SiO₂

   {

   →

   heat}

   2 MgO + Si

   2 Mg + Si

   {

   →

   heat}

   M₂Si // follows from reaction above

   4 Mg + SiO₂

   {

   →

   heat}

   2 MgO + Mg₂Si // overall reaction

2. Combine products with dilute hydrochloric acid