CHEMISTRY GLOSSARY

ether    →   eter

Ethers are organic compounds with a formula R-O-R, where R is not equal to H. They may be derived from alcohols by elimination of water, but the major method is catalytic hydration of olefins. They are volatile highly flammable compounds; when containing peroxides they can detonate on heating. The term ether is often used synonymously with diethyl ether.

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.

fat    →   mast

Fats are esters of glycerol and long chain carboxylic acids. Fats occur widely in plants and animals as a means of storing food energy, having twice the calorific value of carbohydrates. Fats derived from plants and fish generally have a greater proportion of unsaturated fatty acids than those from mammals. Fats may be either solid or liquid at room temperature, depending on their structure and composition. Unsaturated fats are liquid at room temperature.

Plant oils may be hardened by the addition of hydrogen atoms, converting double bonds to single bonds. This process is known as hydrogenation. Hydrogenated vegetable oils are often present in margarine and other processed foods.

Alkali hydrolysis of fat with sodium hydroxide it gives glycerol and soap (i.e. a mixture of the sodium salts of the fatty acids).

micelle    →   micele

Micelle is an electrically charged colloidal particle, usually organic in nature, composed of aggregates of large molecules, e.g., in soaps and surfactants. For aqueous solutions, the hydrophilic end of the molecule is on the surface of the micelle, while the hydrophobic end (often a hydrocarbon chain) points toward the centre.

Millon’s reaction    →   Millonova reakcija

Millon’s reaction is used for testing proteins by the appearance of red colour which the proteins give by reacting with a solution of mercury in nitric acid.

filter paper    →   filtar papir

Filter paper is a quantitative paper used for filtering and made of pure cellulose treated with hydrochloric and hydrofluoric acid. This kind of paper burns out practically without any remains (less than 0.0001 g ashes). Different types of paper are marked with numbers; qualitative bears marking 595 or 597 and quantitative 589 or 590. Dependable upon precipitate character, different types of filter paper are used:

• black band (589¹) - 100 mL of fluid flows through it in 20 s to 30 s. It is used for filtering of gelatinous precipitates.
• white band (589²) - 100 mL of fluid flows through it in 40 s to 60 s. It is used for coarse crystalline precipitates filtration.
• blue band (589³) - 100 mL of fluid flows through it in 200 s to 400 s. It is used for fine crystalline precipitates.

mineralization    →   mineralizacija

Mineralization is a process in which organic compounds (e.g. dead plant or animal material) are converted to inorganic compounds (e.g. nitrate, carbon dioxide).

mutagenic substance    →   mutagena tvar

Mutagenic substances are substances that cause mutation, a change in inheritable properties of an organism.

natural resins    →   prirodne smole

Natural resins are organic compounds which are secreted by some plants and insects. They are used as adhesives, and are very often unsoluble in water.

neptunium    →   neptunij

Neptunium was discovered by Edwin M. McMillan and P. H. Abelson (USA) in 1940. Named after the planet Neptune. It is rare, silvery radioactive metal. Resists alkalis; reacts with oxygen and acids. Attacked by steam. Radiotoxic. Neptunium was produced by bombarding uranium with slow neutrons.