Baking soda and soda ash are similar, yet have a different chemical makeup, reactions and uses. Baking soda, known as sodium bicarbonate (NaHCO3) is composed of one atom of sodium, one atom of hydrogen, one atom of carbon and three atoms of oxygen. Soda ash, known as sodium carbonate (Na2CO3) is made from two atoms of sodium, one atom of carbon and three atoms of oxygen. In both compounds, the sodium will separate from the carbon when mixed with water, but their responses are different. When baking soda breaks down, it vacillates between an acid and base state, while soda ash becomes a base, which can be used to neutralize acids.
Baking soda is a common ingredient in cooking. When mixed with water and an acid, it gives off carbon dioxide gas, which causes the baked goods to rise. This effervescent byproduct makes baking soda a helpful ingredient in carbonated drinks as well. Sodium bicarbonate has numerous additional uses; it is a deodorizer, an ingredient in toothpaste, a cleaning agent, provides relief for canker sores, and is used to draw the venom from insect and jellyfish stings. It can also extinguish small fires, repel ants and roaches, and keep rabbits from eating garden plants.
pH (potential of hydrogen) measurements reveal whether a substance is acidic or alkaline, or an acid or base. pH levels are measured on a scale from zero to 14; the lower the number, the more acidic the substance. Swimming pools should have a pH balance in the midrange, which will allow the chlorine to work effectively without burning the skin or eyes of the swimmers. Soda ash is more alkaline than baking soda, and is the preferred additive to raise the pH levels in swimming pools.
One of the first uses of sodium carbonate was glassmaking, which dates back thousands of years to glass production in Egypt. Centuries later, glass production is still the primary consumer of soda ash. It is also an important ingredient in soaps, detergents, dyes and manufacturing processes. Paper manufacturing uses sodium carbonate to soften the wood particles in pulp.
Sodium carbonate was originally derived from the ashes of burnt seaweed, though sodium carbonate can be gleaned from the ashes of many plants, as well as from table salt. In Green River, Wyoming, a prehistoric lakebed contains around 200 trillion tons of a mineral deposit called trona, which is basically sodium sesquicarbonate. The trona deposit is located between layers of sandstone and shale, and is mined and processed into sodium carbonate. Other natural deposits of sodium carbonate can be found around the world, including Africa, Asia and the Middle East. Baking soda, on the other hand, is not mined, but is a byproduct of soda ash production.
Soda ash can also be produced synthetically using the Solvay process, created by a Swiss chemist in the nineteenth century. Some countries, such as Australia and India, produce sodium carbonate from limestone, salt and coke. Currently, China is the leading producer of soda ash, though the United States follows at a close second, and competition between the two countries is stiff. Following the US, leading producers are Russia, Germany, India, Poland, Italy, France, and the UK.