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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 ...
Flat boat dish is an oblong, flat-bottomed dish, in which it is easy to weigh out the substance, and then move it the reaction chamber, but is not recommended for hygroscopic or air-reactive samples. A tall-shaped dish - it is elongated, oblong, flat-bottomed dish, used when the solid is transferred without a funnel. Other types
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 ...
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.
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 ...
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]
Quinoline is a heterocyclic aromatic organic compound with the chemical formula C 9 H 7 N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, especially if exposed to light, become yellow and later brown.
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 ...