CHEMISTRY GLOSSARY

normal boiling point    →   normalno vrelište

Normal boiling point is a temperature at which pressure of liquid vapour is 101 325 Pa.

octane number    →   oktanski broj

Octane number is the assay mark of the liquid motor fuel which shows its anti-knock value. n-heptane, which detonates very easily, has o.n. 0, whereas isooctane, which does not detonate, has o.n. 100. By mixing these hydrocarbons we obtain fuels of different qualities, with values of octane number between 0 and 100.

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.

organic solvent    →   organsko otapalo

Organic solvent is an organic liquid in which organic (non-polar) substances melt.

ozonide    →   ozonid

Ozonides are explosive organic compounds, mainly oleaginous foul liquids. They emerge in the process of ozonization from some satiated compounds. They are important for structure determining.

permeability    →   permeabilnost

Permeability (Latin permeare, to pass through) is a passage or diffusion of a gas, vapour, liquid, or solid through a material without physically or chemically affecting it.

plastic sulphur    →   plastični sumpor

Plastic sulphur is the shape of sulphur which emerges when hot, liquid sulphur pours out in the water. It can be stretched in long fibres is unstable unstable. It easily solidifies.

filtration    →   filtriranje

Filtration is a procedure in which liquids are separated from the precipitate by passing a suspension through the filter. The precipitate remains on the filter and through it the filtrate passes. Gaseous heterogeneous mixtures can also be filtrated.

foam    →   pjena

Foams are dispersions of gases in liquids or solids. The gas globule may be of any size, from colloidal to macroscopic, as in soap bubbles. Bakers’ bread and sponge rubber are examples of solid foams. Typical liquid foams are those used in fire-fighting, shaving creams, etc. Foams made by mechanical incorporation of air are widely used in the food industry (e.g. whipped cream, egg white, ice cream, etc.). Foams can be stabilized by surfactants.

fractional distillation    →   frakcijska destilacija

Fractional distillation is a procedure in which liquids of close boiling points are separated. It is conducted in fraction or rectification columns in a way that vapour phase created by distillation is condensed and the condensate thus obtained is redistilled. The procedure is repeated several times. Vapour phase always contains more volatile component than the liquid phase, at top of the column vapour of clean volatile component gets out and at the bottom of the column liquid of nonvolatile component.