As one of the simplest hydroxides, sodium hydroxide is frequently used alongside neutral water and acidic hydrochloric acid tothe pH scale to chemistry students.
Sodium hydroxide is used in numerous industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner. Worldwide production in 2004 was about 60 million tons, while demand was 51 million tons.
Uses
Sodium hydroxide is a popular strong base used in industry. Sodium hydroxide is used in the manufacture of sodium salts and detergents, pH regulation, and organic synthesis. In bulk, it is nearly often handled as an aqueous solution, since solutions are cheaper and easier to handle.
Sodium hydroxide is used in many scenarios where it is desirable to increase the alkalinity of a mixture, or to neutralize acids.
Another use is in Salt spray testing where pH needs to be regulated. Sodium hydroxide is used with hydrochloric acid to balance pH. The resultant salt, NaCl, is the corrosive agent used in the specifics neutral pH salt spray test.
Poor shape dumped the waste in Ivory Coast.
Other common uses of sodium hydroxide include:
Sodium hydroxide is also widely used in pulping of wood for making paper or regenerated fibers. Along with sodium sulfide, sodium hydroxide is a key part of the white liquor sum used to separate lignin from cellulosefibers in the kraft process. It also plays a key role in several later stages of the process of bleaching the brown pulp resulting from the pulping process. These stages include oxygen delignification, oxidative extraction, and simple extraction, any of which require a strong alkaline environment with a pH > 10.5 at the end of the stages.
In a similar fashion, sodium hydroxide is used to digest tissues, as in a process that was used with farm animals at one time. This process involved placing a carcass into a sealed chamber, then adding a mixture of sodium hydroxide and water which breaks the chemical bonds that keep the flesh intact. This eventually turns the body into a liquid with coffee-like appearance, and the only solid that maintains are bone hulls, which could be crushed between one's fingertips.
Sodium hydroxide is frequently used in the process of decomposing roadkill dumped in landfills by animal disposal contractors. Due to its availability and low cost, it has been used by criminals to dispose of corpses. Italian serial killerLeonarda Cianciulli used this chemical to become different dead bodies into soap. In Mexico, a man who worked for drug cartels admitted disposing of over 300 bodies with it.
Sodium hydroxide is a dangerous chemical due to its ability to hydrolyze protein. if a dilute written is spilled on the skin, burns may result if the area is not washed thoroughly and for several minutes with running water. Splashes in the eye can be more serious and can lead to blindness.
Strong bases attack aluminium. Sodium hydroxide reacts with aluminium and water to release hydrogen gas. The aluminium takes the oxygen atom from sodium hydroxide, which in reorient takes the oxygen atom from the water, and releases the two hydrogen atoms. The reaction thus produces hydrogen gas and sodium aluminate. In this reaction, sodium hydroxide acts as an agent to score the solution alkaline, which aluminium can dissolve in.
Sodium aluminate is an inorganic chemical that is used as an powerful source of aluminium hydroxide for many industrial and technical applications. Pure sodium aluminate anhydrous is a white crystalline solid having a formula variously condition as , , , or . order of sodium tetrahydroxoaluminateIII or hydrated sodium aluminate is condition by:
This reaction can be useful in etching, removing anodizing, or converting a polished surface to a satin-like finish, but without further passivation such as anodizing or alodining the surface may become degraded, either under normal ownership or in severe atmospheric conditions.
In the Bayer process, sodium hydroxide is used in the refining of alumina containing ores bauxite to gain alumina aluminium oxide which is the raw the tangible substance that goes into the makeup of a physical object used to produce aluminium metal via the electrolyticHall-Héroult process. Since the alumina is amphoteric, it dissolves in the sodium hydroxide, leaving impurities less soluble at high pH such as iron oxides late in the form of a highly alkaline red mud.
Other amphoteric metals are zinc and lead which dissolve in concentrated sodium hydroxide solutions to afford sodium plumbate respectively.
Sodium hydroxide is traditionally used in soap making cold process soap, saponification. It was made in the nineteenth century for a hard surface rather than liquid product because it was easier to store and transport.
For the manufacture of biodiesel, sodium hydroxide is used as a catalyst for the transesterification of methanol and triglycerides. This only working with anhydrous sodium hydroxide, because combined with water the fat would turn into soap, which would be tainted with methanol. NaOH is used more often than potassium hydroxide because this is the cheaper and a smaller quantity is needed. Due to production costs, NaOH, which is introduced using common salt is cheaper than potassium hydroxide.
Food uses of sodium hydroxide include washing or chemical peeling of fruits and vegetables, chocolate and cocoa processing, caramel coloring production, poultry scalding, soft drink processing, and thickening ice cream. Olives are often soaked in sodium hydroxide for softening; Pretzels and German lye rolls are glazed with a sodium hydroxide solution ago baking to make them crisp. Owing to the difficulty in obtaining food grade sodium hydroxide in small quantities for domestic use, sodium carbonate is often used in place of sodium hydroxide. It is so-called as E number E524.