CHEMISTRY GLOSSARY

synthesis    →   sinteza

Synthesis is a formation of a complex product from simpler reactants. For example, water can be synthesised from oxygen and hydrogen gas:

Wohler’s synthesis    →   Wohlerova sinteza

Wöhler’s synthesis is a synthesis of urea performed by the German chemist Friedrich Wöhler (1800-1882) in 1828. He discovered that urea (CO(NH₂)₂) was formed when a solution of ammonium isocyanate (NH₄NCO) was evaporated. At the time it was believed that organic substances such as urea could only be made by living organisms, and its production from an inorganic compound was a notable discovery.

acetal    →   acetal

Acetals are organic compounds having the structure R₂C(OR’)₂ (R’ ≠ H). They are organic compounds formed by addition of alcohol molecules to aldehyde or ketone molecules. Originally, the term was confined to derivatives of aldehydes (one R = H), but it now applies equally to derivatives of ketones (neither R = H ). Mixed acetals have different R’ groups. The formation of acetals is reversible; acetals can be hydrolysed back to aldehydes (ketone) in acidic solutions.

Acetal, 1,1-diethoxyethane (CH₃CH(OC₂H₅)₂), is an organic compound, pleasant smelling, formed by addition of ethyl alcohol to ethanal (acetaldehyde). It is used as a solvent and in synthetic organic chemistry.

acylaction reaction    →   reakcije aciliranja

Acylaction reaction involves the introduction of an acyl group (RCO-) into a compound. An alkyl halide is reacted with an alcohol or a carboxylic acid anhydride e.g.

The introduction of an acetyl group (CH₃CO-) is acetylation, a process used for protecting -OH groups in organic synthesis.

alkanes    →   alkani

Alkanes (paraffins) are acyclic branched or unbranched hydrocarbons having the general formula C_nH_2n+2, and therefore consisting entirely of hydrogen atoms and saturated carbon atoms. In the systematic chemical nomenclature alkane names end in the suffix -ane. They form a homologous series (the alkane series) methane (CH₄), ethane (C₂H₆), propane (C₃H₈), butane (C₄H₁₀), etc. The lower members of the series are gases; the high-molecular mass alkanes are waxy solid. Generaly the alkanes are fairly unreactive. They form haloalkanes with halogens when irradiated with ultraviolet radiation. Alkanes are present in natural gas and petroleum.

chlorine    →   klor

Chlorine was discovered by Carl William Scheele (Sweden) in 1774. The origin of the name comes from the Greek word chloros meaning pale green. It is greenish-yellow, disagreeable gas with irritating odour. Gas is toxic and severe irritant by contact or inhalation. Never found in free form in nature. Commercial quantities of chlorine are produced by electrolysis of aqueous sodium chloride (NaCl) from seawater or brine from salt mines. Used in water purification, bleaches, acids and many, many other compounds such as chlorofluorocarbons (CFC).

dienes    →   dieni

Dienes are unsaturated organic compounds that contain two fixed double bonds between carbon atoms. Dienes in which the two double-bond units are linked by one single bond are termed conjugated.

electroorganic reaction    →   elektroorganske reakcije

Electroorganic reaction is an organic reaction produced in an electrolytic cell. Electroorganic reactions are used to synthesise compounds that are difficult to produce by conventional techniques. An example of an electroorganic reaction is Kolbe’s method of synthesising alkanes.

Haber, Fritz    →   Haber, Fritz

Fritz Haber (1868-1934) is German physical chemist, winner of the Nobel Prize for Chemistry (1918) for his development of a method of synthesizing ammonia. With Carl Bosch, he invented a process for the large-scale production of ammonia for use in nitrogen fertilizer.

carbohydrate    →   ugljikohidrat

Carbohydrates (often called carbs for short) are polyhydroxy aldehydes or ketones, or substances that yield such compounds on hydrolysis. They are also known as saccharides, a term derived from the Latin word saccharum for sugar. Carbohydrates are the most abundant class of compounds in the biological world, making up more than 50 % of the dry weight of the Earth’s biomass. Every type of food we eat can have its energy traced back to a plant. Plants use carbon dioxide and water to make glucose, a simple sugar, in photosynthesis. Other carbohydrates such as cellulose and starch are made from the glucose. Light from the sun is absorbed by chlorophyll and this is converted to the energy necessary to biosynthesize carbohydrates

The term carbohydrate was applied originally to monosaccharides, in recognition of the fact that their empirical composition can be expressed as C_x(H₂O)_y. Later structural studies revealed that these compounds were not hydrates but the term carbohydrate persists.

Carbohydrates are generally classed as either simple or complex. Simple sugars, or monosaccharides, are carbohydrates that can’t be converted into smaller subunits by hydrolysis. Complex carbohydrates are made of two (disaccharides) or more (oligosaccharides, polysaccharides) simple sugars linked together by acetal (glycosidic) bonds and can be split into the former by hydrolysis.