Sodium bicarbonate is an amphoteric compound. Aqueous solutions are mildly alkaline due to the formation of carbonic acid and hydroxide ion: HCO− 3 + H2O → H 2CO 3 + OH− Sodium bicarbonate can be used as a wash to remove any acidic impurities from a crude liquid, producing a purer sample. Reaction of sodium bicarbonate and an acid produce a salt and carbonic acid, which readily decomposes to carbon dioxide and water: NaHCO3 + HCl → NaCl + H2CO3 H2CO3 → H2O + CO2(g) Sodium bicarbonate reacts with acetic acid (found in vinegar), producing sodium acetate, water, and carbon dioxide: NaHCO3 + CH3COOH → CH3COONa + H2O + CO2(g) Sodium bicarbonate reacts with bases such as sodium hydroxide to form carbonates: NaHCO3 + NaOH → Na2CO3 + H2O Sodium bicarbonate reacts with carboxyl groups in proteins to give a brisk effervescence from the formation of CO 2. This reaction is used to test for the presence of carboxylic groups in protein.[citation needed] Thermal decomposition Above 50 °C, sodium bicarbonate gradually decomposes into sodium carbonate, water and carbon dioxide. The conversion is fast at 200 °C:[10] 2 NaHCO3 → Na2CO3 + H2O + CO2 Most bicarbonates undergo this dehydration reaction. Further heating converts the carbonate into the oxide (at over 850°C):[10] Na2CO3 → Na2O + CO2 These conversions are relevant to the use of NaHCO3 as a fire-suppression agent (BC powder) in some dry powder fire extinguishers. Applications Sodium bicarbonate is used in a process for removing paint and corrosion called sodablasting; the process is particularly suitable for cleaning aluminium panels which can be distorted by other types of abrasive. It can be administered to pools, spas, and garden ponds to raise pH levels.[11] It has weak disinfectant properties,[12][13] and it may be an effective fungicide against some organisms.[14] Because baking soda will absorb musty smells, it has become a reliable method for used-book sellers when making books less malodorous.[15]
Posted on: Sat, 08 Mar 2014 07:46:25 +0000
Trending Topics
Recently Viewed Topics
© 2015