Lye noodles are also known as soda, soda ash, that is edible soda, English name dietaryalkali, the main ingredient is sodium carbonate, the chemical formula of Na2CO3. the texture is rough. Because of the similarity in color, so the differentiation method is mainly through the texture of hand rubbing. It is used to neutralize excess acidity in traditional flour making, a process known as "making alkali".

Sodium carbonate Chinese alias: soda, soda ash; lye powder; lye noodles; heavy ash (heavy sodium carbonate); light ash (light sodium carbonate); high purity sodium carbonate; edible soda (edible sodium carbonate). It is an important basic chemical raw material. Soda chemical formula for Na?CO?, soluble in water, its aqueous solution is alkaline. Soda form of colorless crystals, the water of crystallization is unstable, easy to weather, so the ordinary case of white powder, a strong electrolyte, with the generality of salt and thermal stability.

Properties

Sodium carbonate is a white powder or granule at room temperature. No odor. It is a strong base and weak acid salt. It has water absorption. Gradually absorbs 1 mol/L water (about 15%) when exposed to air. Decomposes and effervesces when exposed to acid. Soluble in water (3.5 parts at room temperature, 2.2 parts at 35℃) and glycerol, slightly soluble in anhydrous ethanol. Aqueous solution is strongly alkaline, pH 11.6. relative density (25°C) 2.53.

Melting point 851°C. LD50 (30 days) (mouse, intraperitoneal) 116.6mg/kg. irritating. Can be produced by chemical reaction of sodium hydroxide and carbonic acid combined. The solution is alkaline. Sodium carbonate decomposes at 2132K.