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Example of saponification reaction of a triglyceride molecule (left) with potassium hydroxide (KOH) yielding glycerol (purple) and salts of fatty acids ().. Saponification value or saponification number (SV or SN) represents the number of milligrams of potassium hydroxide (KOH) or sodium hydroxide (NaOH) required to saponify one gram of fat under the conditions specified.
Saponification is a process of cleaving esters into carboxylate salts and alcohols by the action of aqueous alkali. Typically aqueous sodium hydroxide solutions are used. [ 1 ] [ 2 ] It is an important type of alkaline hydrolysis .
In 1935, Linus Pauling used the ice rules to calculate the residual entropy (zero temperature entropy) of ice I h. [3] For this (and other) reasons the rules are sometimes mis-attributed and referred to as "Pauling's ice rules" (not to be confused with Pauling's rules for ionic crystals). A nice figure of the resulting structure can be found in ...
The third stable eutectic has 18.4% (mass) of NaOH. It solidifies at about −28.7 °C as a mixture of water ice and the heptahydrate NaOH·7H 2 O. [18] [22] When solutions with less than 18.4% NaOH are cooled, water ice crystallizes first, leaving the NaOH in solution. [18] The α form of the tetrahydrate has density 1.33 g/cm 3.
An H 2 O molecule that is in the solid phase (ice) has a higher chemical potential than a water molecule that is in the liquid phase (water) above 0 °C. When some of the ice melts, H 2 O molecules convert from solid to the warmer liquid where their chemical potential is lower, so the ice cube shrinks. At the temperature of the melting point, 0 ...
Fats and oils are composed of triglycerides; three molecules of fatty acids are attached to a single molecule of glycerol. [9] The alkaline solution, which is often called lye (although the term "lye soap" refers almost exclusively to soaps made with sodium hydroxide), brings about a chemical reaction known as saponification.
The driving mechanism for micellization is the transfer of hydrocarbon chains from water into the oil-like interior. This entropic effect is called the hydrophobic effect. Compared to the increase of entropy of the surrounding water molecules, this hydrophobic interaction is relatively small. The water molecules are highly ordered around the ...
Water (H 2 O) is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue.It is by far the most studied chemical compound [20] and is described as the "universal solvent" [21] and the "solvent of life". [22]