Volumetrijske metode analize

undergraduate thesis

• Title (english): Volumetric methods of analysis
• Author: Maja Jurenec
• Mentor: Anita Ptiček Siročić (mentor)
• Committee member: Sanja Kovač (predsjednik povjerenstva)
• Committee member: Anita Ptiček Siročić (član povjerenstva)
• Committee member: Nikola Sakač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Geotechnical Engineering; Varaždin
• Defense date and country: 2022-09-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Interdisciplinary Technical Sciences; Environmental Engineering

Abstract

Volumetrijske metode pripadaju skupini kvantitativnih analitičkih metoda. Takve metode temeljenje su na mjerenju utrošenog volumena otopine reagensa poznate koncentracije (titrant) koji je potreban da bi se odvila potpuna reakcija s analiziranom tvari (analit). Takav postupak mjerenja naziva se titracija, te se volumetrijske metode često nazivaju i titrimetrijske metode. Reakcije na temelju kojih se provode mjerenja u volumetriji moraju biti brze, ireverzibilne, stehiometrijski definirane, osjetljive i specifične. Vrlo je važno da u točki ekvivalencije nastane uočljiva promjena kemijskih i fizikalnih svojstava otopine, budući da ona služi za zaustavljanje titracije. Tvari koje se koriste za uočavanje završne točke titracije nazivaju se indikatori. To su tvari koje moraju obojiti titriranu otopinu i kod vrlo niskih koncentracija. Analit se određuje pomoću standardnih otopina točno poznate koncentracije. Standardne tvari dijele se na primarne ili sekundarne standarde ovisno o njihovim svojstvima. Ovisno o vrsti kemijske reakcije, volumetrijske metode možemo podijeliti na kiselo-bazne titracije, redoks titracije, taložne titracije te kompleksometrijske titracije. Kiselo-bazne titracije osnivaju se na reakcijama između baza i kiselina, a nazivaju se i neutralizacijske titracije. Redoks titracije temeljene su na kemijskim reakcijama oksidacije i redukcije u kojim se izmjenjuju elektroni. Kod taložnih titracija, prilikom reakcije standardne otopine i reagensa formira se teško topljiv talog, dok su kompleksometrijske titracije temeljene na reakcijama stvaranja kompleksa.

Abstract (english)

Volumetric methods belong to a group of quantitative analytical methods.
Such methods are based on the measurement of the used volume of a reagent solution of a known concentration (titrant), which is required for a complete reaction with the analysed substance (analyte). Such a measurement procedure is called titration, and volumetric methods are often called titrimetric methods. The reactions on the basis of which measurements are carried out in volumetrics must be fast, irreversible, stoichiometrically defined, sensitive and specific. It is very important that a noticeable change in the chemical and physical properties of the solution occurs at the equivalence point, since it serves to stop the titration. Substances used to observe the end point of titration are called indicators. These are substances that must colour the titrated solution even at very low concentrations. The analyte is determined using standard solutions of an exactly known concentration. Standard substances are divided into primary or secondary standards depending on their properties.
Depending on the type of a chemical reaction, volumetric methods can be divided into acid-base titrations, redox titrations, precipitation titrations and complex metric titrations. Acid-base titrations are based on reactions between bases and acids, and are also called neutralization titrations. Redox titrations are based on chemical reactions of oxidation and reduction in which electrons are exchanged. In precipitation titrations, during the reaction of a standard solution and a reagent, a hardly soluble precipitate is formed, while complex metric titrations are based on complex formation reactions.

• Keywords: volumetrija; titracija; indikator; analit; titrant; točka ekvivalencije
• Keywords (english): volumetric; titration; indicator; analyte; titrant; equivalence point
• Language: croatian
• URN:NBN: urn:nbn:hr:130:533569
• Study programme: Title: Environmental Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/ baccalaurea) inženjer/ inženjerka inženjerstva okoliša (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/ baccalaurea) inženjer/ inženjerka inženjerstva okoliša)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2022-10-24 09:32:41