Search results
Results From The WOW.Com Content Network
For hydrocarbons, the DBE (or IHD) tells us the number of rings and/or extra bonds in a non-saturated structure, which equals the number of hydrogen pairs that are required to make the structure saturated, simply because joining two elements to form a ring or adding one extra bond (e.g., a single bond changed to a double bond) in a structure reduces the need for two H's.
log(K a) = log(K 0 a) + ρσ. K a is the dissociation constant of a substituted compound, K 0 a is the dissociation constant when the substituent is hydrogen, ρ is a property of the unsubstituted compound and σ has a particular value for each substituent. A plot of log(K a) against σ is a straight line with intercept log(K 0 a) and slope ρ.
In stereochemistry, enantiomeric excess (ee) is a measurement of purity used for chiral substances. It reflects the degree to which a sample contains one enantiomer in greater amounts than the other.
The x-axis of a mass spectrum represents a relationship between the mass of a given ion and the number of elementary charges that it carries. This is written as the IUPAC standard m/z to denote the quantity formed by dividing the mass of an ion (in daltons) by the dalton unit and by its charge number (positive absolute value).
Calcium hypochlorite is a general oxidizing agent and therefore finds some use in organic chemistry. [6] For instance the compound is used to cleave glycols, α-hydroxy carboxylic acids and keto acids to yield fragmented aldehydes or carboxylic acids. [7] Calcium hypochlorite can also be used in the haloform reaction to manufacture chloroform. [8]
A crucible and tongs, on a green mat. The ash content of a sample is a measure of the amount of inorganic noncombustible material it contains. The residues after a sample is completely burnt - in contrast to the ash remaining after incomplete combustion - typically consist of oxides of the inorganic elements present in the original sample.
The concentration is measured in weight of agarose over volume of buffer used (g/ml). For a standard agarose gel electrophoresis, a 0.8% gel gives good separation or resolution of large 5–10kb DNA fragments, while 2% gel gives good resolution for small 0.2–1kb fragments. 1% gels is often used for a standard electrophoresis. [25]
Such compounds follow the law of multiple proportion. An example is the iron oxide wüstite, which can contain between 0.83 and 0.95 iron atoms for every oxygen atom, and thus contain anywhere between 23% and 25% oxygen by mass. The ideal formula is FeO, but it is about Fe 0.95 O due to crystallographic vacancies. In general, Proust's ...