Search results
Results from the WOW.Com Content Network
Quantities, Units and Symbols in Physical Chemistry, also known as the Green Book, is a compilation of terms and symbols widely used in the field of physical chemistry. It also includes a table of physical constants , tables listing the properties of elementary particles , chemical elements , and nuclides , and information about conversion ...
Category for measurements units found in chemistry, mainly in analytical chemistry Pages in category "Units of chemical measurement" The following 14 pages are in this category, out of 14 total.
In chemistry, the amount of substance (symbol n) in a given sample of matter is defined as a ratio (n = N/N A) between the number of elementary entities (N) and the Avogadro constant (N A). Since 2019, the value of the Avogadro constant N A is defined to be exactly 6.022 140 76 × 10 23 mol −1 .
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or submultiple of the unit. All metric prefixes used today are decadic.Each prefix has a unique symbol that is prepended to any unit symbol.
Similar tests for identifying organic compounds (by testing for different functional groups) are also known. Many techniques can be used for either qualitative or quantitative measurements. For instance, suppose an indicator solution changes color in the presence of a metal ion. It could be used as a qualitative test: does the indicator ...
If an automated measurement of a large number of samples is required, modern automatic refractometers can be combined with an automatic sample changer. The sample changer is controlled by the refractometer and assures fully automated measurements of the samples placed in the vials of the sample changer for measurements.
Calorimeters are called active or heated if they heat the sample, or reformulated: if they are gauged to fill the sample with a defined amount of entropy. Actinometer heating power of radiation. Constant-temperature calorimeter , phase change calorimeter for example an ice calorimeter or any other calorimeter observing a phase change or using a ...
Artifact-free definitions fix measurements at an exact value related to a physical constant or other invariable phenomena in nature, in contrast to standard artifacts which are subject to deterioration or destruction. Instead, the measurement unit can only ever change through increased accuracy in determining the value of the constant it is ...