CHEMISTRY GLOSSARY

unsaturated hydrocarbon    →   nezasićeni ugljikovodik

Unsaturated hydrocarbons are organic compounds containing double (alkenes) or triple (alkynes) bonds in their molecules.

halocarbon    →   halogenirani ugljikovodik

Halocarbon is a compound containing no elements other than carbon, one or more halogens, and sometimes hydrogen. The simplest are compounds such as tetrachloromethane (CCl₄), tetrabromomethane (CBr₄), etc. The lower members of the various homologous series are used as refrigerants, propellant gases, fireextinguishing agents, and blowing agents for urethane foams. When polymerized, they yield plastics characterized by extreme chemical resistance, high electrical resistivity, and good heat resistance.

aromatic compounds    →   aromatski ugljikovodici

Aromatic compounds are a major group of unsaturated cyclic hydrocarbons containing one or more rings, typified by benzene, which has a 6-carbon ring containing three double bonds. All the bonds in benzene (C₆H₆) are the same length intermediate between double and single C-C bonds. The properties arise because the electrons in the p-orbitals are delocalised over the ring, giving extra stabilization energy of 150 kJ/mol over the energy of Kekulé structure. Aromatic compounds are unsaturated compounds, yet they do not easily partake in addition reactions.

Historical use of the term implies a ring containing only carbon (e.g., benzene, naphthalene), but it is often generalized to include heterocyclic structures such as pyridine and thiophene.

unsaturated fatty acid    →   nezasićena masna kiselina

Unsaturated fatty acid is a fatty acid whose carbon chain can absorb additional hydrogen atoms. Their carbon chain has one or more double or triple valence bond per molecule. The most important of these are:

hydrocarbon    →   ugljikovodici

Hydrocarbon is a compound containing only carbon and hydrogen.

unsaturated solution    →   nezasićena otopina

Unsaturated solution is a solution that contains less than the maximum possible equilibrium concentration of a solute.

unsaturated fat    →   nezasićena mast

Unsaturated fats, which include one or more unsaturated fatty acid, are liquid at room temperature (oil) and come from plant oils such as olive, peanut, corn, sunflower, safflower, and soybean. The fish oils may also be high in unsaturated fatty acids.

acetylene    →   acetilen

Acetylene (ethyne) is a colourless unstable gas, C₂H₂, with a characteristic sweet odour. It is lighter than air, easily soluble in acetone (propanone) and it is explosive under high pressure.

catalytic hydrogenation    →   katalitičko hidrogeniranje

Catalytic hydrogenation is the infusing of unsaturated or impure hydrocarbons with hydrogen gas at controlled temperatures and pressures and in the presence of a catalyst for the purpose of obtaining saturated hydrocarbons and/or removing various impurities such as sulphur and nitrogen.

alkenes    →   alkeni

Alkenes are acyclic branched or unbranched hydrocarbons having one or more double carbon-carbon bonds in their molecules. In the systematic chemical nomenclature, alkene names end in the suffix -ene. The general formula is C_nH_(2n+2)-2x were x is the number of double bonds. Alkenes that have only one double bond form a homologous series: ethene (ethylene), CH₂=CH₂, propene, CH₃CH₂=CH₂, etc. Alkenes typically undergo addition reactions to the double bond.