Na2SiO3

Sodium silicate, with the chemical formula Na2SiO3, is an inorganic compound commonly known as water glass. It is a salt formed from the cation sodium (Na+) and the silicate anion (SiO3^2-). In its pure form, sodium silicate is a white solid. However, it is more commonly encountered as a solution in water, which can range in color from colorless to yellowish or greenish depending on impurities.

The preparation of sodium silicate typically involves fusing silica sand (silicon dioxide, SiO2) with sodium carbonate (soda ash, Na2CO3) at high temperatures in a furnace. The reaction is 2 Na2CO3 + SiO2 → Na2SiO3 + 2 CO2. Alternatively, it can be produced by dissolving silica in a hot solution of sodium hydroxide.

Sodium silicate is a versatile chemical with numerous industrial applications. It is widely used as a binder in cements, refractories, and foundry molds. Its detergent properties make it a common additive in laundry soaps and industrial cleaners, where it helps to soften water and emulsify grease. In the paper industry, it acts as a de-inking agent. It also finds use in the production of adhesives, as a flux in welding rods, and in the manufacture of silica gel, a desiccant. In the food industry, it is used as a preservative for eggs and as an anticaking agent.