Sodium bicarbonate

Sodium bicarbonate, which is also called bicarbonate of soda or sodium hydrogen carbonate, is a white crystalline powder. In everyday use, it is best known as baking soda. Sodium bicarbonate has many uses, such as an ingredient in baking, a household cleaner, a medical treatment, a fire-extinguishing agent, and more. People use sodium bicarbonate, whose chemical formula is NaHCO₃, both from natural sources and from human production. Sodium bicarbonate has numerous applications as a reactive substance that produces carbon dioxide when it is involved in a chemical reaction.

Background

Humans have used sodium bicarbonate for hundreds of years, even before totally understanding its chemical properties or how to produce it. Sodium carbonate is found in a natural mineral form called nahcolite. Nahcolite deposits exist in numerous locations around the world, and they are common near sources of water. One of the largest US sources of nahcolite is in Colorado. One way to capture nahcolite is to pump warm water around the crystalline structures. Nahcolite deposits often occur naturally close to oil and gas deposits.

In the 1700s, humans were using numerous natural resources, including nahcolite, to produce goods such as glass in factories. As industrialization increased, the demand for these resources also increased. At the same time, chemistry was becoming an important form of science that helped humans create some of the resources they needed to create goods.

In the 1780s, the French Academy of Sciences offered a prize to a scientist who could develop a method for producing alkali substances, which were needed in the production of goods, from common salt (sodium chloride). A French scientist named Nicolas Leblanc developed a method by reacting sulfuric acid with common salt (sodium chloride) to make sodium sulfate and hydrochloric acid. He then added other ingredients to make calcium sulfide, carbon dioxide, and sodium carbonate—which is soda ash. Sodium carbonate could then easily be turned into sodium bicarbonate.

Leblanc’s discovery was a revolution in industry, though he did not benefit from it. A Belgian chemist named Ernest Solvay learned from LeBlanc’s method and developed his own way to create sodium bicarbonate, which was then easily transformed into sodium carbonate. Solvay’s improvement on sodium bicarbonate happened in the 1860s, and it made producing sodium bicarbonate easier than ever. Eventually, new methods overtook the Solvay method as well.

Overview

Sodium bicarbonate is naturally a white solid, but it is usually formed into a white crystalline powder. It is an alkaline substance with a pH of 8.5 (in a 1 percent aqueous solution at 25°C, or 77°F). It is one of the most alkaline sodium compounds. The chemical’s alkalinity gives it a slightly bitter taste. Sodium bicarbonate is a reactive compound and decomposes from heat and from other chemical reactions. The substance begins to decompose when heated over 50°C (122°F). When the substance decomposes, it forms carbon dioxide, sodium carbonate, and water. Because of its alkalinity, sodium bicarbonate exhibits a strong reaction when mixed with acids. It will release gas when mixed with water and heated; however, it will release twice as much gas when it is mixed with water, heated, and mixed with an acid.

Sodium bicarbonate has numerous applications in science, industry, and the home. One of the most common applications is in baking. In the early 1800s, people began using baking soda as a leavening agent in bread and other baked goods. When the sodium bicarbonate is mixed with a liquid in a baking mix, heated, and introduced to a sufficient amount of acid, it creates bubbles that add air into baked items. Because sodium bicarbonate releases more gas when it is mixed with an acid, bakers often ensure that products made with baking soda also include some type of acid, such as yogurt, buttermilk, or chocolate.

The acidic catalyst is helpful for leavening purposes because, on contact with the sodium bicarbonate, it causes the release of carbon dioxide in a simple acid-base reaction. Alternatively, baking soda can release smaller volumes of carbon dioxide without an acid simply via the process of thermal decomposition at temperatures above 50°C, although this typically leaves a characteristic bitter flavor. Either way, the release of gas into the mixture as it cooks changes a dish’s density and texture.

People eventually developed another chemical leavening agent called baking powder. Baking powder includes some baking soda in it, but it also includes enough acid to activate all the soda. Because of this, baking powder can be used in recipes in which no other acid is added. Chemical leavening agents helped cooks of all different experience levels successfully bake many types of foods, which before could have been risen only with yeast or by whipping air into eggs or batter.

Cleaning is another common application for sodium bicarbonate. The properties of sodium bicarbonate cause it to remove odors, and people sprinkle it on surfaces or add it to water when washing clothes. People also place containers of sodium bicarbonate in refrigerators and other areas that might have smells, as the compound can help absorb the odors. People also use sodium bicarbonate to clean other surfaces, including polishing silver or scrubbing mildew off plastic. Studies have shows that sodium bicarbonate also helps break down and remove pesticides from the surfaces of fruits and vegetables.

People also use sodium bicarbonate as a medicine or treatment for minor health problems. One of the popular medical applications for sodium bicarbonate is for indigestion. It helps neutralize acid in the digestive system, helping to relieve heartburn. People also commonly use it, either on its own or as an additive in toothpaste, to help clean and whiten teeth. Research indicates that sodium bicarbonate can also help individuals with chronic kidney disease. The studies suggest that people with chronic kidney disease can experience improved renal function after receiving sodium bicarbonate orally.

Sodium bicarbonate is a popular medical treatment in part because it is nontoxic. However, it does increase people’s sodium levels, so people who are supposed to monitor their sodium intake should talk to a healthcare provider before using sodium bicarbonate. Furthermore, people should talk to a healthcare provider before allowing children under twelve to use the treatment. Some common side effects of ingesting sodium bicarbonate are gas, stomach cramps, and increased thirst. People should be aware that some over-the-counter treatments, including some antacids, include sodium bicarbonate.

Bibliography

Cheng, F., Li, Q., et al. “The Effects of Oral Sodium Bicarbonate on Renal Function and Cardiovascular Risk in Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis.” Therapeutics and Clinical Risk Management, vol. 17, 2021, pp. 1321–31.

Graves, Alice, and Kate Qualmann. “The Science of Baking Soda.” ACS Publications, 3 Aug. 2018, axial.acs.org/2018/08/03/the-science-of-baking-soda/. Accessed 4 Dec. 2024.

Krystal, Becky. “Baking Powder vs. Baking Soda: How They’re Different, Which to Use When and More.” The Washington Post, 21 June 2021, www.washingtonpost.com/food/2021/06/21/baking-powder-baking-soda-differences/. Accessed 4 Dec. 2024.

Martin, Christy, and Brigitte Van Tiggelen. “Making the Process.” Science History Institute, 5 Dec. 2011, www.sciencehistory.org/distillations/making-the-process. Accessed 4 Dec. 2024.

McNeil, Megan. Western Slope Home to One of World’s Largest Baking Soda Mines.” NBC 11 News, 14 Feb. 2018, www.nbc11news.com/content/news/Western-Slope-home-to-one-of-worlds-largest-baking-soda-mines-474102433.html. Accessed 4 Dec. 2024.

Pfister, Raymond. “Natural Soda Uses Wireless Technology to Monitor Mining Operations.” International Society of Automation, Mar. 2017, www.isa.org/intech-home/2017/march-april/features/natural-soda-uses-wireless-to-monitor-mines. Accessed 4 Dec. 2024.

Rodriguez-Velazquez, Sorangel. “5.6: Sodium Bicarbonate.” LibreTexts Chemistry, 11 Sept. 2021, chem.libretexts.org/Bookshelves/Biological‗Chemistry/Chemistry‗of‗Cooking‗(Rodriguez-Velazquez)/05%3A‗Leavening‗Agents/5.06%3A‗Sodium‗Bicarbonate. Accessed 4 Dec. 2024.

“Sodium Bicarbonate.” MedlinePlus, National Library of Medicine, 15 Apr. 2017, medlineplus.gov/druginfo/meds/a682001.html. Accessed 4 Dec. 2024.

Sutton, Mike. “A Revolutionary Casualty.” Chemistry World, 30 Oct. 2006, www.chemistryworld.com/features/a-revolutionary-casualty/3004475.article. Accessed 4 Dec. 2024.