CHEMISTRY GLOSSARY

chlorophyll    →   klorofil

Chlorophyll is a green pigment present in green plants and cyanobacteria. Chlorophyll is essential in the transformation of light energy to chemical energy in photosynthesis. Chlorophyll absorbs light mostly in the blue and red ends of the visible spectrum, and very little in the green wavelengths. That green light is reflected, giving us the leaf colour we see.

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.

dehydrogenation    →   dehidrogenacija

Dehydrogenation is a chemical reaction in which hydrogen is removed from a compound. Dehydrogenation of organic compounds converts single carbon-carbon bonds into double bonds. It is usually affected by means of a metal catalyst or in biological systems by enzyme dehydrogenases.

coenzyme    →   koenzim

Coenzyme is an organic nonprotein molecule, such as a vitamin, that associates with an enzyme in catalysing biochemical reactions. Coenzymes usually participate in the substrate-enzyme interaction by donating or acepting certain chemical groups.

collision theory    →   teorija sudara

Collision theory is theory that explains how chemical reactions take place and why rates of reaction alter. For a reaction to occur the reactant particles must collide. Only a certain fraction of the total collisions cause chemical change; these are called successful collisions. The successful collisions have sufficient energy (activation energy) at the moment of impact to break the existing bonds and form new bonds, resulting in the products of the reaction. Increasing the concentration of the reactants and raising the temperature bring about more collisions and therefore more successful collisions, increasing the rate of reaction.

colloid ion    →   koloidni ion

Colloid ions emerge when colloid particles adsorb certain type of ion from solution and thus become charged with the same charge. The charge can also originate form a chemical reaction of colloid particle’s surface. Colloid ions formed by absorption of silver chloride particle can be show as follows:

Adsorbed layer is monomolecular (one molecule thick) and which type of ion will be formed depends upon which ions are present in a greater number in the solution in. Because of this colloid particles are charged with the same charge, mutual repelling occurs, and the colloid solution becomes stable. Colloid charge can be determined by electrophoresis.

condensation    →   kondenzacija

1. Condensation is a process of changing from a gaseous to a liquid or solid state, usually done by cooling.

2. Condensation, in colloid systems, is a process where smaller particle join in one colloid size particle

3. Condensation, in chemical terms, is a sort of chemical reaction in which small molecules like water, carbon dioxide, or ammonia single out.

corrosion    →   korozija

Corrosion is a harmful and undesirable construction material consumption by the chemical activity of its surroundings. Corrosion concept refers to metal and nonmetal construction materials, but it is usually used for metals, Corrosion of metal, according to the mechanism process, is divided into chemical (corrosion in nonelectrolytes) and electrochemical (corrosion in electrolytes).

Chemical corrosion appears by direct action of molecule of some element or compound on metal, thus directly creating corrosion products.

Electrochemical corrosion of metals occurs in electrolytes, so reduction of metal atom into free cation appears which by secondary processes gives molecules of compound which are considered a corrosion product.

detergent    →   deterdžent

Detergent is a substance added to water to improve its cleaning properties. Although water is a powerful solvent for many compounds, it will not dissolve grease and natural oils. Detergents are compounds that cause such nonpolar substances to go into solution in water. Soap is the original example, owing its action to the presence of ions formed from long-chain fatty acids ion (e.g. stearat ion, CH₃(CH₂)₁₆COO^-).

effervescence    →   pjenušanje

Effervescence is the formation of gas bubbles in a liquid by a chemical reaction. An example of effervescence is the release of carbon dioxide which bubbles as a gas from the liquid when limestone chips, which are composed of calcium carbonate, are added to dilute hydrochloric acid.