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The diluted material must be thoroughly mixed to achieve the true dilution. For example, in a solution with a 1:5 dilution ratio, entails combining 1 unit volume of solute (the material to be diluted) with 5 unit volumes of the solvent to give 6 total units of total volume. In photographic development, dilutions are normally given in a '1+x ...
If one begins with a solution of 1 mol/L of a substance, the dilution required to reduce the number of molecules to less than one per litre is 1 part in 1×10 24 (24X or 12C) since: 6.02×10 23 /1×10 24 = 0.6 molecules per litre
The dilution in welding terms is defined as the weight of the base metal melted divided by the total weight of the weld metal. For example, if we have a dilution of 0.40, the fraction of the weld metal that came from the consumable electrode is 0.60.
A tenfold dilution for each step is called a logarithmic dilution or log-dilution, a 3.16-fold (10 0.5-fold) dilution is called a half-logarithmic dilution or half-log dilution, and a 1.78-fold (10 0.25-fold) dilution is called a quarter-logarithmic dilution or quarter-log dilution.
To calculate phenol coefficient, the concentration of phenol at which the compound kills the test organism in 10 minutes, but not in 5 minutes, is divided by the concentration of the test compound that kills the organism under the same conditions (or, probably more common, dividing the dilution factor at which the tested substance shows ...
Adding of an isotopically altered standard to the sample changes the natural isotopic composition of the analyte. By measuring the resulting isotopic composition, it is possible to calculate the amount of the analyte present in the sample. Isotope dilution analysis is a method of determining the quantity of chemical substances. In its most ...
Conversely, in an indirect dilution assay the dose levels are administered at fixed dose levels, so that the response is a stochastic variable. In some assays, there may be strong reasons for believing that all the constituents of the test preparation except one, are without any effect on the studied response of the subjects.
Titres are sometimes expressed by the denominator only, for example 1:256 is written 256. [3] The term also has two other, conflicting meanings. In titration, the titer is the ratio of actual to nominal concentration of a titrant, e.g. a titer of 0.5 would require 1/0.5 = 2 times more titrant than nominal. This is to compensate for possible ...