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Appears in:
Pages: 3341-3346
Publication year: 2020
ISBN: 978-84-09-17979-4
ISSN: 2340-1117
doi: 10.21125/edulearn.2020.0955

Conference name: 12th International Conference on Education and New Learning Technologies
Dates: 6-7 July, 2020
Location: Online Conference

SYSTEMATIC DESIGN OF ACID-BASE TITRATIONS FOR UNDERGRADUATE STUDENTS: APPLICATION TO THE RESOLUTION OF A MIXTURE OF TWO AMINO ACIDS

Titrimetric methods remain very important in the curriculum of chemistry students. They are classical quantitative methods of analysis directly related to dissolution equilibria, which continue to be used in quality control. In general, titrimetries are fast and simple analysis methods that require only glassware for their implementation, so that they are easily adaptable to any practice laboratory. Direct titrimetries are usually carried out in these educational practices in which the titrant is added directly to the sample using a chemical indicator suitable for the detection of the equivalence point. However, in very few cases, the student understands all the conditions in which the titrimetry must be developed. This is especially pronounced in the case of titrating a mixture of two or three analytes. This is because in this type of practice a behavioral teaching model is followed. A systematic study of this topic is necessary in order to offer students a tool that can be used to understand and design different titrimetries. The Prof. Gaston Charlot, in the 1940s, offered an interesting approach of ionic chemical reactions based on a very simple model (donor-acceptor model), which in turn was based on Brønsted and Lowry theory [1]. The model proposed by G. Charlot has been related with the constructivism used nowadays for teaching of sciences [2]. Subsequently, it was complemented by A. Ringbon [3].

In this work, using Charlot´s approach, an acid-base titration is designed. A study case is presented: a mixture of two substances with acid-base characteristics, arginine hydrochloride (diprotic acid, pK1 = 1.8 and pK2= 8.9) and histidine hydrochloride (triprotic acid, pK1 = 1.7, pK2 = 6.0 and pK3 = 8.8). Therefore, as a starting point, a strong base (NaOH) as titrant and 0.1 M concentrations are used.

References:
[1] G. Charlot, Cours de chimie analytique génerále, Masson, Paris, 1969.
[2] M.R. Gómez-Moliné, A. Rojas-Hernández, M.T. Ramírez-Silva, Educación química, 2009, 20, 192-197, El constructivismo y la química analítica del profesor Gaston Charlot, http://www.scielo.org.mx/pdf/eq/v20n2/v20n2a14.pdf
[3] A. Ringbom, Complexation in analytical Chemistry, J. Wiley and Sons Inc., 1963.
@InProceedings{DELACALLE2020SYS,
author = {de la Calle, I. and Lavilla, I. and Pena, F.J. and Romero, V. and Bendicho, C.},
title = {SYSTEMATIC DESIGN OF ACID-BASE TITRATIONS FOR UNDERGRADUATE STUDENTS: APPLICATION TO THE RESOLUTION OF A MIXTURE OF TWO AMINO ACIDS},
series = {12th International Conference on Education and New Learning Technologies},
booktitle = {EDULEARN20 Proceedings},
isbn = {978-84-09-17979-4},
issn = {2340-1117},
doi = {10.21125/edulearn.2020.0955},
url = {http://dx.doi.org/10.21125/edulearn.2020.0955},
publisher = {IATED},
location = {Online Conference},
month = {6-7 July, 2020},
year = {2020},
pages = {3341-3346}}
TY - CONF
AU - I. de la Calle AU - I. Lavilla AU - F.J. Pena AU - V. Romero AU - C. Bendicho
TI - SYSTEMATIC DESIGN OF ACID-BASE TITRATIONS FOR UNDERGRADUATE STUDENTS: APPLICATION TO THE RESOLUTION OF A MIXTURE OF TWO AMINO ACIDS
SN - 978-84-09-17979-4/2340-1117
DO - 10.21125/edulearn.2020.0955
PY - 2020
Y1 - 6-7 July, 2020
CI - Online Conference
JO - 12th International Conference on Education and New Learning Technologies
JA - EDULEARN20 Proceedings
SP - 3341
EP - 3346
ER -
I. de la Calle, I. Lavilla, F.J. Pena, V. Romero, C. Bendicho (2020) SYSTEMATIC DESIGN OF ACID-BASE TITRATIONS FOR UNDERGRADUATE STUDENTS: APPLICATION TO THE RESOLUTION OF A MIXTURE OF TWO AMINO ACIDS, EDULEARN20 Proceedings, pp. 3341-3346.
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