CHEMISTRY GLOSSARY

molar fraction    →   molarni udio

See Amount fraction

amount fraction    →   količinski udio

Amount fraction, x_A, (y for gaseous mixtures) is the ratio of the amount of substance (number of moles) of substance A to the total amount of substance in a mixture.

fraction    →   udio

Fraction is a ratio of two quantities of the same kind, the numerator quantity applying to one constituent (or part) of the system and the denominator to the sum of quantities for all constituents (parts) of the system. When applied to mixtures fractions represent a group of three quantities: mass fraction, volume fraction and amount fraction (or mole fraction equal to the number fraction).

molar absorption coefficient    →   molarni apsorpcijski koeficijent

Molar absorption coefficient (ε) is the absorption coefficient divided by amount-of-substance concentration of the absorbing material in the sample solution (ε = a/c). The SI unit is m²mol^-1. Also called extinction coefficient, but usually in units of dm³cm^-1mol^-1.

molar volume    →   molarni volumen

Molar volume is the volume occupied by substance per unit amount of substance. The volume of the gas at 0 °C and 101 325 Pa is 22.4 dm³mol^-1.

mass fraction    →   maseni udio

Mass fraction (w_A) is the ratio of the mass of substance A to the total mass of a mixture.

mole fraction    →   molni udio

See Amount fraction

volume fraction    →   volumenski udio

Volume fraction (φ_A) is defined as

where V_A is the volume of the specified component and the V_i are the volumes of all the components of a mixture prior to mixing.

molar enthalpy of evaporation    →   molarna entalpija isparavanja

Molar enthalpy of evaporation (Δ_l ^gH) is a change of enthalpy during evaporation divided by molarity of a liquid, and is equal to the heat energy spent when the evaporation is conducted under constant pressure, Δ_l ^gH=Q.

molar enthalpy of melting    →   molarna entalpija taljenja

Molar enthalpy of melting (Δ_s ^lH) is a change of enthalpy during melting divided by the molarity of a solid matter, and is equal to the energy used when melting is conducted under constant pressure.