Silicon tetrachloride synthesis

Silicon is heated in a tube with chlorine

Scientific name: Synthesis of silicon tetrachloride at high temperature

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Silicon tetrachloride 2

by ChemPics

Silicon Tetrachloride making

by ChemPics

Safety

Wear eye protection and lab gloves. This experiment must be performed in a fume hood.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

2 KMnO4 + 16 HCl → 2 KCl + 2 MnCl2 + 8 H2O + 5 Cl2

Si + 2Cl2 → SiCl4

Step-by-step instruction

WARNING! This experiment is dangerous! You should NOT perform this at home. ONLY carry out this experiment, if you are a trained chemist, and you understand local safety and legal requirements, which are required to perform such experiments

  1. Chlorine gas production is needed for this experiment. For the synthesis of chlorine gas use a round-bottom flask with about 5 g of potassium permanganate inside and dropping funnel filled with hydrochloric acid. Dropwise add hydrochloric acid to potassium permanganate to produce chlorine gas.
  2. Place the silicon powder in a porcelain boat in a glass tube.
  3. Connect one end of the tube with a chlorine gas feed and another one with the product collector. Produced chlorine gas from the round-bottom flask should pass through sulfuric acid for drying. Silicon tetrachloride may be collected in a cooling receiving vessel. For the absorption of chlorine, the vessel should be connected with the vessels filled with concentrated sodium hydroxide solution.
  4. When chlorine is being produced with a uniform rate and fills the apparatus, heat silicon with a burner.
  5. After 0.5 - 1 ml of product has been collected, finish heating of the tube and cool it in a steam of chlorine gas.

Scientific background

Potassium permanganate reacts with hydrochloric acid forming chlorine

HCl+KMnO4 → KCl + MnCl2 + Cl2 + H2O

Silicon reacts with produced chlorine forming silicon tetrachloride, a yellow-orange liquid, which condenses in the receiving vessel.

Danger:
Coolness:
Difficulty:

Published on 01 July 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst