CHEMISTRY GLOSSARY

crucible    →   lončić za žarenje

Crucible is used for heating small amounts of solid in an oven to very high temperatures. Crucibles are usually made out of porcelain, platinum, nickel or iron.

crude oil    →   sirova nafta

Crude oil (petroleum) is a fossil fuel formed from plant and animal remains many million of years ago. It is occasionally found in springs or pools but is usually drilled from wells beneath the earth’s surface. Crude oil is a mixture of hydrocarbons with small quantities of other chemicals such as sulphur, nitrogen and oxygen. Crude is the raw material which is refined into petrol, heating oil, jet fuel, propane, petrochemicals, and other products.

crystallisation    →   kristalizacija

Crystallisation is process in which the melted substance from a saturated solution turns into solid substance (crystal).

decomposing    →   raščinjavanje

Decomposing in analytical chemistry means that a certain substance is converted, by melting it with a suitable melting medium (sodium carbonate, sodium hydroxide, sodium peroxide, ...) in the kind of compound which will afterwards that dissolve in water, acid or base very easily.

depression of freezing point    →   snižavanje ledišta

Depression of freezing point of a pure solvent is observed when substances are dissolved in it. The amount by which the freezing point is depressed is proportional to the number of molecules of solute and independent of their nature.

dilute solution    →   razrijeđena otopina

Dilute solution contains a relatively low concentration of solute.

dye    →   bojilo

Dyes are substances used to impart colour to textiles, leather, paper, etc. Compounds used for dyeing are generally organic compounds containing conjugated double bonds. In practice dyes are classified according to the way in which the dye is applied or is held on the substrate.

Curie temperature    →   Curiejeva temperatura

For a ferromagnetic material, Curie temperature or Curie point (T_C) is the critical temperature above which the material becomes paramagnetic. For iron the Curie point is 760 °C and for nickel 356 °C. It was named after the French physicist Pierre Curie (1859-1906).

density    →   gustoća

In the most common usage, density (ρ) is mass density or mass per unit volume. In Si units it is measured in kg m^-3. More commonly, densities are given in kg dm^-3.

More generally, it is the amount of some quantity (mass, charge, energy, etc.) divided by a length, area, or volume.

Relative density is the ratio of the density of a substance to the density of some reference substance. For liquids or solids, it is the ratio of the density (usually at 20 °C) to the density of water at 4 °C. This quantity was formerly called specific gravity.

dialysis    →   dijaliza

Dialysis is a method by which large molecules (such as starch or protein) and small molecules (such as glucose or amino acids) may be separated in a solution by selective diffusion through a semipermeable membrane. Through this kind of membrane dissolved particles pass and colloid dimension particles fall behind. For example, if a mixed solution of starch and glucose is placed in a closed container made of a semipermeable substance (such as cellophane), which is then immersed in a beaker of water, the smaller glucose molecules will pass trough the membrane into the water, while the starch molecules remain behind.