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Ammonia Solution
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH3(aq). Although the name ammonium hydroxide suggests an alkali with composition , it is actually impossible to isolate samples of NH4OH. The ions and OH− do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions. Basicity of ammonia in water In aqueous solution, ammonia deprotonates a small fraction of the water to give ammonium and hydroxide according to the following equilibrium: : NH3 + H2O NH4+ + OH−. In a 1 M ammonia solution, about 0.42% of the ammonia is converted to ammonium, equivalent to pH = 11.63 because H4+ = 0.0042 M, H− = 0.0042 M, H3 = 0.9958 M, and pH = 14 + log10 H− = 11.62. The base ionization constant is : ''K''b = H4+OH−] / H3= 1.77. Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formaldehyde
Formaldehyde ( , ) ( systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Forms below), hence it is stored as an aqueous solution (formalin), which is also used to store animal specimens. It is the simplest of the aldehydes (). The common name of this substance comes from its similarity and relation to formic acid. Formaldehyde is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated at 8.7 million tons per year. It is mainly used in the production of industrial resins, e.g., for particle board and coatings. Forms Formaldehyde is more complicated than many simple carbon compounds in that it adopts several diverse forms. These compounds can often be used interchangeably and can be interconverted. *Molecular for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Carbonate
Ammonium carbonate is a salt with the chemical formula (NH4)2CO3. Since it readily degrades to gaseous ammonia and carbon dioxide upon heating, it is used as a leavening agent and also as smelling salt. It is also known as baker's ammonia and is a predecessor to the more modern leavening agents baking soda and baking powder. It is a component of what was formerly known as sal volatile and salt of hartshorn, and produces a pungent smell when baked. Production Ammonium carbonate is produced by combining carbon dioxide and aqueous ammonia. About 80,000 tons/year were produced as of 1997. An orthorhombic monohydrate is known. It crystallizes in an ammonia solution exposed in a carbon dioxide-rich atmosphere. Decomposition Ammonium carbonate slowly decomposes at standard temperature and pressure through two pathways. Thus any initially pure sample of ammonium carbonate will soon become a mixture including various byproducts. Ammonium carbonate can spontaneously decompose into amm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Food Timeline
Lynne Olver (1958–2015) was a librarian and food historian, and the sole author of the Food Timeline website. Personal life Olver graduated from the University of Albany (SUNY). She was a librarian at the Morris County Library, New Jersey, and became its director in 2009. The Food Timeline In 1999, Olver created ''The Food Timeline'', a history website documenting culinary history, food history and recipes. The website has since become a major information source for culinary history. Almost all of the website's information comes from Lynne's personal library of over 2,000 books. Unlike many other food related websites, Olver gave citations to almost every statement on her site so that readers can verify her claims. Her research has been cited in peer-reviewed journals. Following her death, the site was given to her family, who chose to remove social media accounts associated with the Food Timeline, but kept the website running in a state of dormancy. As such, the websit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leavening Agent
In cooking, a leavening agent () or raising agent, also called a leaven () or leavener, is any one of a number of substances used in doughs and batters that cause a foaming action (gas bubbles) that lightens and softens the mixture. An alternative or supplement to leavening agents is mechanical action by which air is incorporated (i.e. kneading). Leavening agents can be biological or synthetic chemical compounds. The gas produced is often carbon dioxide, or occasionally hydrogen. When a dough or batter is mixed, the starch in the flour and the water in the dough form a matrix (often supported further by proteins like gluten or polysaccharides, such as pentosans or xanthan gum). The starch then gelatinizes and sets, leaving gas bubbles that remain. Biological leavening agents * ''Saccharomyces cerevisiae'' producing carbon dioxide found in: ** baker's yeast ** Beer barm (unpasteurised—live yeast) ** ginger beer ** kefir ** sourdough starter * ''Clostridium perfringens' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
