Search results
Results From The WOW.Com Content Network
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.
Lithium hydroxide is an inorganic compound with the formula LiOH. It can exist as anhydrous or hydrated, and both forms are white hygroscopic solids. They are soluble in water and slightly soluble in ethanol. Both are available commercially. While classified as a strong base, lithium hydroxide is the weakest known alkali metal hydroxide.
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
Example 2: Consider a larger block of the same stone material as in Example 1 but with a 1-liter cavity inside of the same amount of stone. The block would still weigh 3 kilograms on dry land (ignoring the weight of air in the cavity) but it would now displace 2 liters of water so its immersed weight would be only 1 kilogram (at 4 °C).
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 ...