CHEMISTRY GLOSSARY

nonelectrolyte    →   neelektrolit

Nonelectrolytes are substances which in solutions do not dissociate into ions and they do not conduct electric current.

oil    →   ulje

Oils are triglycerides containing a high percentage of unsaturated fatty acids.

osmosis    →   osmoza

Osmosis is the flow of a solvent in a system in which two solutions of different concentration are separated by a semipermeable membrane which cannot pass solute molecules. The solvent will flow from the side of lower concentration to that of higher concentration, thus tending to equalise the concentrations. The pressure that must be applied to the more concentrated side to stop the flow is called the osmotic pressure.

electrophoresis    →   elektroforeza

Electrophoresis is a technique for the analysis and separation of colloids, based on the movement of charged colloidal particles in an electric field. The migration is toward electrodes of charge opposite to that of the particles. The rate of migration of the particles depends on the field, the charge on the particles, and on other factors, such as the size and shape of the particles.

Electrophoresis is important in the study of proteins. The acidity of the solution can be used to control the direction in which a protein moves upon electrophoresis.

electroplating    →   galvaniziranje

Electroplating (also called electrodeposition) is the deposition of a metallic coating onto an object by putting a negative charge onto the object and immersing it into a solution which contains a salt of the metal to be deposited. The metallic ions of the salt carry a positive charge and are attracted to the part. When they reach it, the negatively charged part provides the electrons to reduce the positively charged ions to metallic form.

Typically, a brass or nickel object is coated with a layer of silver by making use of electrolysis of a silver solution, using the object to be coated as the cathode. The anode consist of pure silver, and the cathode is the object to be plated. The electrolyte is a mixure of silver nitrate with potassium cyanide. The reactions are:

The cyanide ensures a low concentration of silver ions, a condition for providing the best plating results.

Erlenmeyer flask    →   Erlenmeyerova tikvica

Erlenmeyer flask is a glass container which has a narrow, cylindrical mouth and a cone-shaped main body that ends in a wide, flat bottom. It was named after its inventor, a German chemist Richard Erlenmeyer (1825-1909). Erlenmeyer flasks are most often used in titrations to hold the liquid that is being titrated.

ozonolisys    →   ozonoliza

Ozonolisys is a procedure of adding ozone to an unsaturated organic compound, by which first ozonides emerge, and then degrade.

perfume    →   parfem

Perfumes are mixtures or alcohol solutions of natural or synthetic volatile substances of a pleasant aroma, usually containing plant ethereal oils or relative esters, ethers, aldehydes and ketones.

polyens    →   polieni

Polyens are unsaturated acyclic compounds with many conjugated double connections between atoms of carbon (CH₂=CH-CH=CH-CH=CH₂).

extraction    →   ekstrakcija

Extraction is the separation of a component from its mixture by selective solubility. When a solution of one substance in one solvent is brought in with another solvent dissolved substance will distribute between the two solutants because of different solubility. Extraction is an efficient and fast method used for separating and concentrating matters. Extraction is best done several times in a succession, with smaller amount of solvent in it the matter is better dissolved. For example, caffeine can be separated from coffee beans by washing the beans with supercritical fluid carbon dioxide; the caffeine dissolves in the carbon dioxide, but flavour compounds do not. Vanillin can be extracted from vanilla beans by shaking the beans with an organic solvent, like ethanol.