CHEMISTRY GLOSSARY

acid dissociation constant    →   konstanta disocijacije kiseline

Acid dissociation constant (K_a) is the equilibrium constant for the dissociation of an acid HA through the reaction

The quantity pK_a = -log K_a is often used to express the acid dissociation constant.

constant    →   konstanta

Constant in a quantity that does not vary, e.g. in formula pV=RT, R is a universal constant and is equal to 8.314 J mol^-1 K^-1, while p, V and T are variables.

cryoscopic constant    →   krioskopska konstanta

Cryoscopic constant (E_f) is the constant that expresses the amount by which the freezing point T_f of a solvent is lowered by a non-dissociating solute, through the relation

where m is the molality of the solute.

crystal water    →   kristalna voda

Crystal water is water contained in certain salt crystals. It can be removed by heating. Crystals that contain crystal water are called hydrated and their salts hydrates.

crystalline substance    →   kristalna tvar

Crystalline substances are substances that contain crystals.

diffraction grating    →   difrakcijska rešetka

Diffraction grating is a series of slits used to separate an incident wave into its component wavelengths by directionally separating their diffraction maxima.

ebullioscopic constant    →   ebulioskopska konstanta

Ebullioscopic constant (E_b) is the constant that expresses the amount by which the boiling point T_b of a solvent is raised by a nondissociating solute, through the relation

where b is the molality of the solute.

Boltzmann constant    →   Boltzmannova konstanta

The Boltzmann constant (k or k_B) is the physical constant describing the relationship between the thermodynamic temperature and the average kinetic energy of particles in a gas. It equals the molar gas constant R divided by the Avogadro constant N_A and has the value 1.380 648 52(79)×10^-23 J/K. It is named after the Austrian physicist Ludwig Eduard Boltzmann (1844-1906).

Faraday constant    →   Faradayeva konstanta

Faraday constant (F) is the electric charge of 1 mol of singly charged positive ions.

where N_A is Avogadro’s constant (6.022×10²³ mol^-1) and e is the elementary charge (1.602×10^-19 C).

gravitational constant    →   gravitacijska konstanta

Gravitational constant (G) is the universal constant in the equation for the gravitational force between two particles

where r is the distance between the particles and m₁ and m₂ are their masses.