CHEMISTRY GLOSSARY
ligand field theory → teorija ligandnog polja
Ligand field theory is a description of the structure of crystals containing a transition metal ion surrounded by nonmetallic ions (ligands). It is based on the construction of molecular orbitals involving the d-orbitals of the central metal ion and combinations of atomic orbitals of the ligands.
differential thermal analysis → diferencijalna termalna analiza
Differential thermal analysis (DTA) is a technique that is often used to analyze materials that react or decompose at higher temperatures. The difference in temperature between the sample and an inert reference material is monitored as both are heated in a furnace. Phase transitions and chemical reactions taking place in the sample on heating cause the temperature difference to become larger, at temperatures that are characteristic of the sample.
Neel temperature → Neelova temperatura
Néel temperature (TN) is the critical temperature above which an antiferromagnetic substance becomes paramagnetic. The phenomenon was discovered around 1930 by the French physicist L.E.F. Néel (1904-2000).
organoleptic testing → organoleptičko ispitivanje
Organoleptic testing of matter is a testing of matter and material using the senses of sight, smell, taste and touch, used usually when buying groceries.
photoelectric threshold → fotoelektrični prag
Photoelectric threshold is a maximum length of electromagnetic wave which can still cause the photoelectric effect.
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 The test is now rarely used, having been replaced by Benedict’s test.
polymorphic transition → polimorfni prijelaz
Polymorphic transition is a reversible transition of a solid crystalline phase at a certain temperature and pressure to another phase of the same chemical composition with a different crystal structure. For examples, the transitions of quartz (SiO2) at 1 143 K to tridymite, and at 1 743 K to cristobalite.
Fischer-Tropsch process → Fischer-Tropschov postupak
Fischer-Tropsch process is an industrial method of making hydrocarbon fuels from carbon monoxide and hydrogen. The process was introduced in 1933. and used by Germany in World War II. to produce motor fuel. Hydrogen and carbon monoxide are mixed in the ratio 2:1 (water gas was used with added hydrogen) and passed at 200 °C over a nickel or cobalt catalyst. The resulting hydrocarbon mixture can be separated into a higher-boiling fraction for Diesel engines and a lower-boiling petrol fraction. The petrol fraction contains a high proportion of straight-chain hydrocarbons and has to be reformed for use in motor fuel. Alcohols, aldehydes, and ketones are also present. The process is also used in the manufacture of SNG from coal. It is named after the German chemist Franz Fischer (1852-1932) and the Czech Hans Tropsch (1839-1935).
retention time → retencijsko vrijeme
Retention time is time between incentive (sample injection) and recall (appearance of signal on detector).
surface tension → površinska napetost
Surface tension (σ) is a property of liquids arising from unbalanced molecular cohesive forces at or near the surface, as a result of which the surface tends to contract and has properties resembling those of a stretched elastic membrane. As a result of which the surface tends to contract and has properties resembling those of a stretched elastic membrane.
Citing this page:
Generalic, Eni. "Ledište." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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