RT other
T1 A formaldehyde-based assay for ammonium N in fertilizers. Interactive exercise.
A1 Milla González, Miguel
A2 Química Analítica
K1 Acid-base titrations
K1 Ammonium N determination
K1 Fertilizer
K1 Formaldehyde-based ammonium N determination
K1 Ammonium N assay
K1 N determination in fertilizers
K1 Interacive exercise
K1 Stoichiometric calculations
AB Ammonium salts react with formaldehyde with quantiative release of protons that can be titrated with NaOH solution to phenolphthalein endpoint. In this interactive exercise it is made use of this property to describe an assay for ammonium N in fertilizers. After weighing the sample (selecting one of three weighing ranges), the analyst must dissolve the fertilizer in a volumetric flask of his choice and take an aliquot of this solution for analysis. The addition of excess neutral formaldehyde brings about the release of protons that are titrated with NaOH solution. For calculations, a puzzle-like correct stoichiometric expression must be set up which allows entering the found value of N percentage in the fertilizer sample. This result is finally checked. All the data are generated randomly.
YR 2013
FD 2013-06-11T00:00:00Z
LK http://hdl.handle.net/10498/15373
UL http://hdl.handle.net/10498/15373
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 04-oct-2023