<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0187-893X</journal-id>
<journal-title><![CDATA[Educación química]]></journal-title>
<abbrev-journal-title><![CDATA[Educ. quím]]></abbrev-journal-title>
<issn>0187-893X</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Facultad de Química]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0187-893X2023000200040</article-id>
<article-id pub-id-type="doi">10.22201/fq.18708404e.2023.2.83275</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Demostración práctica de la importancia de la longitud de onda en la espectroscopía Ultravioleta Visible]]></article-title>
<article-title xml:lang="en"><![CDATA[Practical demonstration of the importance of wavelength in Ultraviolet Visible spectroscopy]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Amaya Vesga]]></surname>
<given-names><![CDATA[Álvaro Andrés]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Carvajal Grimaldos]]></surname>
<given-names><![CDATA[Astrid Carolina]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gómez Tarazona]]></surname>
<given-names><![CDATA[Raúl Armando]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Mendoza Castellanos]]></surname>
<given-names><![CDATA[Yeisson Ricardo]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de Santander Facultad de Ciencias Exactas, Naturales y Agropecuarias, Ciencias Básicas y Aplicadas Para la Sostenibilidad ]]></institution>
<addr-line><![CDATA[Bucaramanga ]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad de Santander Facultad de Ciencias Exactas, Naturales y Agropecuarias ]]></institution>
<addr-line><![CDATA[Bucaramanga ]]></addr-line>
<country>Colombia</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>00</month>
<year>2023</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>00</month>
<year>2023</year>
</pub-date>
<volume>34</volume>
<numero>2</numero>
<fpage>40</fpage>
<lpage>49</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0187-893X2023000200040&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0187-893X2023000200040&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0187-893X2023000200040&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen En el presente trabajo se llevó a cabo el diseño de una serie de experimentos que tienen como objetivo brindar a los docentes de cursos de química analítica, herramientas que les permitan demostrar de manera práctica la importancia de la selección de la longitud de onda de análisis en las mediciones de absorbancia en la disciplina de la espectroscopía de ultravioleta visible. Inicialmente, se plantearon una serie de experimentos basados en la absorción de radiación por parte de soluciones de azul de metileno y azul de bromotimol (con pH regulado a 3,7) a diferentes concentraciones. Para ello, se hizo pasar un haz de color rojo (665 nm) y violeta (405 nm) sobre una serie de soluciones de azul de metileno y azul de bromotimol a estudiar y se observó de forma cualitativa la atenuación de la intensidad (o potencia) del haz de radiación después de salir de la celda, teniendo en cuenta que, a mayor atenuación o disminución de la intensidad de la radiación, mayor sería la absorbancia por parte de la muestra. Seguidamente, se propuso un experimento en el laboratorio basado en la realización de curvas de calibración de azul de metileno y azul de bromotimol (regulado a pH de 3,7) a diferentes longitudes de onda (665 y 425 nm), con el fin de proveerle información cuantitativa al estudiante sobre la importancia de la selección de la longitud de onda en aplicaciones de la espectroscopía de absorción ultravioleta visible. Finalmente, los experimentos más representativos del presente trabajo fueron enmarcados en una serie de experimentos cortos de fácil realización, los cuales permiten facilitar la adquisición de conceptos mediante la interacción directa con los fenómenos a estudiar.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract In the present work, the design of a series of experiments was carried out with the objective of providing teachers of analytical chemistry courses with tools that allow them to demonstrate in a practical way the importance of the analysis wavelength in the measurements of absorbance in the, discipline of visible ultraviolet spectroscopy. Initially, a series of experiments based on the absorption of radiation by methylene blue and bromothymol blue (with pH regulated at 3.7) at different concentrations are proposed. To do this, the red (665 nm) and violet (405 nm) colored beam was passed over the solution to be studied and the attenuation of the intensity (or power) of the radiation beam was observed qualitatively after leaving the solution cell, considering that the greater the attenuation or decrease in the intensity of the radiation, the greater the absorbance of the sample. Finally, an experiment is proposed in the laboratory based on the realization of calibration curves of methylene blue and bromothymol blue (regulated at pH 3.7) at different wavelengths (665 and 425 nm), to provide quantitative information to the student about the importance of the selection of the wavelength in applications of visible ultraviolet absorption spectroscopy.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Espectroscopía ultravioleta visible]]></kwd>
<kwd lng="es"><![CDATA[Absorbancia]]></kwd>
<kwd lng="es"><![CDATA[Longitud de onda]]></kwd>
<kwd lng="en"><![CDATA[Ultraviolet - Visible Spectroscopy]]></kwd>
<kwd lng="en"><![CDATA[Absorbance]]></kwd>
<kwd lng="en"><![CDATA[Wavelength]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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