How to turn liquid glass and food additives into “plastic”
Obtaining a self-solidifying liquid
Wear protective gloves, eyewear, and a mask. Perform this experiment in a well-ventilated area.
Reagents and equipment
- 2 g calcium hydroxide (food additive Е526);
- 10 mL distilled water with dye;
- 15 mL liquid glass (sodium silicate solution);
- a wooden stick;
- 2 disposable plastic cups;
- a Petri dish.
In one of the two cups, mix 2 g of calcium hydroxide with 10 mL of distilled water tinted with food coloring. Add 15 mL of liquid glass (sodium silicate solution). Pour the liquid back and forth between the two cups to mix. Watch the mass solidify with time.
The reaction of liquid glass (usually a sodium silicate solution) with calcium hydroxide (food additive Е526) forms an insoluble precipitate of calcium silicate. Since calcium hydroxide is poorly soluble in water, the calcium silicate crystals begin to grow on the surface of the insoluble calcium hydroxide particles. Over time, the crystals intertwine to form a solid mass reminiscent of a polymer – firm and able to retain its shape.
Na₂SiO₃ + Ca(OH)₂ = CaSiO₃ + 2NaOH