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There is no standard quantitative definition of hygroscopicity, so generally the qualification of hygroscopic and non-hygroscopic is determined on a case-by-case basis. For example, pharmaceuticals that pick up more than 5% by mass, between 40 and 90% relative humidity at 25 °C, are described as hygroscopic, while materials that pick up less ...
A humectant / h juː ˈ m ɛ k t ən t / is a hygroscopic (water-absorbing) substance used to keep things moist. They are used in many products, including food, cosmetics, medicines and pesticides. When used as a food additive, a humectant has the effect of keeping moisture in the food. [1]
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
A desiccant is a hygroscopic substance that is used to induce or sustain a state of dryness (desiccation) in its vicinity; it is the opposite of a humectant. Commonly encountered pre-packaged desiccants are solids that absorb water. Desiccants for specialized purposes may be in forms other than solid, and may work through other principles, such ...
It was the first known example of a molecule that is an intrinsic semiconductor. [20] [21] It exhibits electrochromism, changing color when subject to a voltage. It is a double-decker sandwich compound consisting of a Lu 3+ ion coordinated to two the conjugate base of two phthalocyanines. The rings are arranged in a staggered conformation.
Many substances are hygroscopic, meaning they attract water, usually in proportion to the relative humidity or above a critical relative humidity. Such substances include cotton, paper, cellulose, other wood products, sugar, calcium oxide (burned lime) and many chemicals and fertilizers. Industries that use these materials are concerned with ...
The Hygroscopic Cycle is a concept that has evolved recently and is at the heart of intensive research on hygroscopic fluids. Recent developments have been the Kalina cycle , [ 17 ] but with the actual configuration, it is expected to have an impact in locations with poor access to water, and a good integration with combined cycle plants, and ...
The lower compartment of the desiccator contains lumps of silica gel, freshly calcined quicklime, Drierite, molecular sieves, phosphorus pentoxide, (not as effective) anhydrous calcium chloride, or other desiccant to absorb water vapor.