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Here, a primary standard is typically a reagent which can be weighed easily, and which is so pure that its weight is truly representative of the number of moles of substance contained. Features of a primary standard include: High purity; Stability (low reactivity) Low hygroscopicity (to minimize weight changes due to humidity)
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 .
The volume of a particular material or compound is affected by ambient moisture and may be considered its coefficient of hygroscopic expansion (CHE) (also referred to as CME, or coefficient of moisture expansion) or the coefficient of hygroscopic contraction (CHC)—the difference between the two terms being a difference in sign convention.
The toxicity of this compound is similar to toxicity of choline itself, which is fairly low, and it is used as a dietary supplement. Oral LD 50 value for a human is estimated to be 200 to 400 grams (as choline). Nevertheless, choline bitartrate can be harmful, if absorbed through skin. It may cause skin, eye and respiratory system irritation.
More modern isotherms showing the sorption of water vapor, on the vertical axis, provide the ratio of the weight of water adsorbed divided by its dry weight, or that ratio converted into a percentage. On the horizontal axis they provide relative humidity or water activity of the air presented to the material.
Hydroxylammonium nitrate or hydroxylamine nitrate (HAN) is an inorganic compound with the chemical formula [NH 3 OH] + [NO 3] −. It is a salt derived from hydroxylamine and nitric acid. In its pure form, it is a colourless hygroscopic solid. It has potential to be used as a rocket propellant either as a solution in monopropellants or ...
Mass fraction can also be expressed, with a denominator of 100, as percentage by mass (in commercial contexts often called percentage by weight, abbreviated wt.% or % w/w; see mass versus weight). It is one way of expressing the composition of a mixture in a dimensionless size ; mole fraction (percentage by moles , mol%) and volume fraction ...
Triethylene glycol is a member of a homologous series of polyethylene glycols.It is a colorless, odorless and stable liquid with high viscosity and a high boiling point. . Apart from its use as a raw material in the manufacture and synthesis of other products, TEG is known for its hygroscopic quality and its ability to dehumidify fl