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The epoxy value is defined as the number of moles of epoxy group per 100g resin. So as an example using an epoxy resin with molar mass of 382 and that has 2 moles of epoxy groups per mole of resin, the EEW = 382/2 = 191, and the epoxy value is calculated as follows: 100/191 = 0.53 (i.e. the epoxy value of the resin is 0.53). [6]
For the moisture content dry basis the ratio of the weight of the water to the weight of the dry matter (1 / (2+2) = 25% in the above example) is used, so the value can be above 100% if there is more water than dry matter in the solution.
It is one way of expressing the composition of a mixture in a dimensionless size; mole fraction (percentage by moles, mol%) and volume fraction (percentage by volume, vol%) are others. When the prevalences of interest are those of individual chemical elements , rather than of compounds or other substances, the term mass fraction can also refer ...
When expressed in percent, it is known as the mole percent or molar percentage (unit symbol %, sometimes "mol%", equivalent to cmol/mol for 10 −2). The mole fraction is called amount fraction by the International Union of Pure and Applied Chemistry (IUPAC) [ 1 ] and amount-of-substance fraction by the U.S. National Institute of Standards and ...
Conversion and its related terms yield and selectivity are important terms in chemical reaction engineering.They are described as ratios of how much of a reactant has reacted (X — conversion, normally between zero and one), how much of a desired product was formed (Y — yield, normally also between zero and one) and how much desired product was formed in ratio to the undesired product(s) (S ...
Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. [1] For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase : [2]
The molar ratio allows for conversion between moles of one substance and moles of another. For example, in the reaction 2 CH 3 OH + 3 O 2 → 2 CO 2 + 4 H 2 O. the amount of water that will be produced by the combustion of 0.27 moles of CH 3 OH is obtained using the molar ratio between CH 3 OH and H 2 O of 2 to 4.
The mass-average molecular mass, M w, is also related to the fractional monomer conversion, p, in step-growth polymerization (for the simplest case of linear polymers formed from two monomers in equimolar quantities) as per Carothers' equation: ¯ = + ¯ = (+), where M o is the molecular mass of the repeating unit.