CHEMISTRY GLOSSARY

ideal solution    →   idealna otopina

Ideal solution is a solution in which solvent-solvent and solvent-solute interactions are identical, so that properties such as volume and enthalpy are exactly additive. Ideal solutions follow Raoult’s law, which states that the vapour pressure p_i of component i is p_i = x_i p_i^*, where x_i is the mole fraction of component i and p_i^* the vapour pressure of the pure substance i.

aqueous solution    →   vodena otopina

Aqueous solutions are those solutions where water is the solvent. An aqueous solution found in an equation describing a chemical reaction is denoted by the state symbol, (aq).

basic liquid    →   matična otopina

Basic liquid is a liquid left after crystallizations.

buffer    →   pufer otopina

Buffer is a solution designed to maintain a constant pH when small amounts of a strong acid or base are added. Buffers usually consist of a fairly weak acid and its salt with a strong base. Suitable concentrations are chosen so that the pH of the solution remains close to the pK_a of the weak acid.

binary solution    →   binarna otopina

Binary solution is a mixture of two liquids that are completely miscible one with another. The boiling point of binary solution depends upon the solution composition and there can be three cases:

1. the boiling points of solutions of all compositions lie between the boiling points of clean liquids

2. the boiling points of solutions of any composition lie above the boiling points of clean liquids

3. the boiling points of solutions of some compositions lie below the boiling points of clean liquids

concentrated solution    →   koncentrirana otopina

Concentrated solution is a solution that contains a large amount of solute relative to the amount that could dissolve.

dilute solution    →   razrijeđena otopina

Dilute solution contains a relatively low concentration of solute.

isotonic solution    →   izotonična otopina

Isotonic solutions are the solutions that have equal osmotic pressure.

non-water solution    →   nevodena otopina

Non-water solution is a solution in which the solvent is not a water (usualy non-polar).

Fehling’s test    →   Fehlingova otopina

Fehling’s test is a chemical test to detect reducing sugars and aldehydes in a solution, devised by the German chemist Hermann Christian von Fehling (1812-1885). Fehling’s solution consists of Fehling’s A (copper(II) sulphate solution) and Fehling’s B (sodium tartarate solution), equal amounts of which are added to the test solution. After boiling, a positive result is indicated by the formation of a brick-red precipitate of copper(I) oxide. Methanal, being a strong reducing agent, also produces copper metal; ketones do not react. The test is now rarely used, having been replaced by Benedict’s test.