“Explosive silane gas” experiment
How to obtain a gas that sparks and pops
Standing ovations are doubtless a performer’s best reward. But for chemists, the substances that they work with can provide all the applause they need! In this experiment, we’ll make silane gas, which makes a clapping sound.
Wear protective gloves, glasses, and a mask.
Perform this experiment in a well-ventilated room.
Observe safety rules when working with heating devices and combustible mixtures.
Warning! Don’t try to repeat this experiment without a professional supervision!
Reagents and equipment:
- 50 mL 10% sulfuric acid solution;
- 3 g dry silicon dioxide;
- 6 g magnesium powder;
- gas burner;
- test tube;
- Petri dish;
Heated silicon dioxide is mixed with magnesium powder in a 1:2 ratio. The mixture is then added to a test tube (the test tube must be held with the neck facing away!), and heated with a gas burner. Diluted sulfuric acid is poured into a Petri dish, and the cooled powder is added to it.
When the mixture of silicon dioxide and magnesium powder is heated, two processes take place at once.
The reduction of silicon from oxide:
SiO₂ + 2Mg = Si + 2MgO
And the reaction of silicon with magnesium, with the formation of magnesium silicide:
Si + 2Mg = Mg₂Si
Magnesium silicide is hydrolyzed in the sulfuric acid solution, and silane gas is released. It self-combusts in air.
Mg₂Si + 2H₂SO₄ = 2MgSO₄ + SiH₄
SiH₄ + 2O₂ = SiO₂ + 2H₂O