CHEMISTRY GLOSSARY

volume ratio    →   volumenski omjer

Volume ratio is equal to volume (V_A) of one component and volume (V_B) of other component’s proportion.

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.

isotope proportion    →   izotopni omjer

Isotope proportion is a number of atoms of each isotope in a sample of one element. It uses relative masses of isotopes to calculate a relative mass of one element.

mass ratio    →   maseni omjer

Mass ratio is equal to the proportion of the mass of one (m_A) and the mass of other component (m_B).

mole ratio    →   količinski omjer

Mole ratio is equal to a proportion of one component quantity (n_A) and the quantity of other component (n_B).

volume concentration    →   volumenska koncentracija

Volume concentration (σ) is equal to volume (V_A) of solute and volume (V) of solution proportion. Volume concentration differs from volume fraction because the sum of solution components volume is almost always different than the solution volume.

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).

solution composition    →   sastav otopine

Solutions are homogenous mixtures of several components. The component which is found in a greater quantity is called the solvent and the other components are called solutes. Quantitative composition of a solution can be expressed by concentration (amount, mass, volume and number), by fraction (amount, mass, and volume), ratio (amount, mass, and volume) and by molality. Amount, mass, and volume ratio are numerical, nondimensional units and are frequently expressed as percentage (% = 1/100), promile (‰ = 1/1000) or parts per million (ppm = 1/1 000 000). If it is not defined, it is always related to the mass ratio.

absorbance    →   apsorbancija

Absorbance (A) is a logarithm of the ratio of incident radiant power (P_o) to transmitted radiant power (P) through a sample (excluding the effects on cell walls).

The absorption of light by a substance in a solution can be described mathematically by the Beer-Lambert law

where A is the absorbance at a given wavelength of light, ε is the molar absorbtivity or extinction coefficient (L mol^-1 cm^-1), unique to each molecule and varying with wavelength, b is the length of light path through the sample (cm), and c is the concentration of the compound in solution (mol L^-1).

abundance of substances    →   rasprostranjenost tvari

Abundance of substances is the ratio of the total mass of a specified element in the Earth’s crust to the total mass of the Earth’s crust. It is often expressed as a percentage.