CHEMISTRY GLOSSARY
equilibrium constant → konstanta ravnoteže
The equilibrium constant (K) was originally introduced in 1863 by Norwegian chemists C.M. Guldberg and P. Waage using the law of mass action. For a reversible chemical reaction represented by the equation
chemical equilibrium occurs when the rate of the forward reaction equals the rate of the back reaction, so that the concentrations of products and reactants reach steady-state values.
The equilibrium constant is the ratio of chemical activities of the species A, B, C, and D at equilibrium.
To a certain approximation, the activities can be replaced by concentrations.
For gas reactions, partial pressures are used rather than concentrations
The units of Kp and Kc depend on the numbers of molecules appearing in the stoichiometric equation (a, b, c, and d).
The value equilibrium constant depends on the temperature. If the forward reaction is exothermic, the equilibrium constant decreases as the temperature rises. The equilibrium constant shows the position of equilibrium. A low value of K indicates that [C] and [D] are small compared to [A] and [B]; i.e. that the back reaction predominates.
The equilibrium constant is related to ΔrG°, the standard Gibbs free energy change in the reaction, by
nitro colour → nitrobojilo
Nitro colours are artificial organic colours that contain nitro-group. They are used for colouring skin, wool and silk.
nitroso compound → nitrozo spoj
Nitroso compounds are compounds that contain the nitroso-group (.NO).
nitrosoamine → nitrozoamin
Nitrosoamines are carcinogenic compounds that contain nitroso and amino-group in a single molecule.
fatty acid → masna kiselina
Fatty acids are aliphatic monocarboxylic acids characterized by a terminal carboxyl group (R-COOH). The higher members of this series of acids occur in nature in the combined form of esters of glycerol (fats), and hence all acids of this family are called fatty acids. Natural fatty acids commonly have a chain of 4 to 28 carbons (usually unbranched and even-numbered), which may be saturated or unsaturated. The most important of saturated fatty acids are butyric (C4), lauric (C12), palmitic (C16), and stearic (C18). The most common unsaturated acids are oleic, linoleic, and linolenic (all C18).
The physical properties of fatty acids are determined by the chain length, degree of unsaturation, and chain branching. Short-chain acids are pungent liquids, soluble in water. As the chain length increases, melting points are raised and water-solubility decreases. Unsaturation and chain branching tend to lower melting points.
freon → freon
Freon (chlorofluorocarbon, CFC) a type of compound in which some or all of the hydrogen atoms of hydrocarbon (usually an alkane) have been replaced by chlorine and fluorine atoms. Most CFC are chemically uncreative and are stable at high temperatures. They are used as aerosol propellants, refrigerants, and solvents, and in the manufacture of rigid packaging foam. CFC because of their chemical inertness, can diffuse unchanged into the upper atmosphere. Here, photochemical reactions cause them to break down and react with ozone. For his reason, their use has been discouraged.
fructose → fruktoza
Fructose (fruit sugar) is a ketohexose (a six-carbon ketonic sugar), which occurs in sweet fruits and honey. Glucose and fructose have the same molecular formula, C6H12O6, but have different structures. Pure, dry fructose is a very sweet, white, odorless, crystalline solid. Fructose is one of the sweetest of all sugars and is combined with glucose to make sucrose, or common table sugar. An older common name for fructose is levulose, after its levorotatory property of rotating plane polarized light to the left (in contrast to glucose which is dextrorotatory). The polysaccharide inulin is a polymer of fructose.
Citing this page:
Generalic, Eni. "Skupine periodnog sustava." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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