ISSN 0187-893X       ISSNE 1870-8404
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Guide authors of the current issue Volumen XXVIII, Número 1, January de 2017 Volumen XXVII, Número 4, October de 2016 Volumen XXVII, Número 3, July de 2016 Volumen XXVII, Número 2, April de 2016
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Number 2,
2017-04-04


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Volume XXVII

Number 2

2016-04-13

COVER OF THIS ISSUE OF THE JOURNAL

Front and back number

   

DIRECTORY

Directory Magazine

   

CONTENT

Content Number 2

   

EDITORIAL

Editorial

José Antonio Chamizo   91 - 92

NOBEL PRIZE

Reparación del ADN: un asunto de vida. . .y de Premios Nobel

Jorge Vázquez Ramos   93 - 96
[+]
DNA repair studies conducted in recent decades by researchers Tomas Lindahl, Paul Modrich and Aziz Sancar were awarded with the 2015 Nobel Prize in Chemistry. Here briefly the basis of this research is presented. All Rights Reserved © 2016 Universidad Nacional Autónoma de México, Facultad de Química. This is an open access item distributed under the Creative Commons CC License BY-NC-ND 4.0.

ACTUALIZED TEACHERS

El crecimiento en los extremos: reactividad de grupos terminales en polímeros para la síntesis de copolímeros bloque

José E. Báez   97 - 104
[+]
Three different cases of reactions using end-groups in polymers were analyzed for the synthesis of block copolymers, such as: a) azide (R N3) and alkine (R C CH) end groups to obtain a 1,3-dipolar cycloaddition (click chemistry), b) ,-hydroxy telechelic polymers (HO R OH) and diisocyanates (OCN R NCO) to synthesize polyurethanes by polycondesation and c) alkyl halides (R Cl or R Br) to prepare block copolymers derived of polystyrene by atom transfer radical polymerization (ATRP).

QUIMIOTRIVIA REJECTA

¿Es el profesor de Química también profesor de Lengua?

Juan Quílez Pardo   105 - 114
[+]
This article analyses the importance of the language of chemistry in the construction, communication and learning of this scientific subject. Some of the most relevant difficulties of the language of chemistry are highlighted. Among them we can find the high number of new terms as well as their different types, and also the scarce attention given by textbooks to the meaningful learning of new vocabulary. To these problems it must be added the lack of opportunities that students experience to produce scientific arguments in the chemistry classroom, which certainly is connected with the difficulty they face to develop higher order thinking skills. Some recommendations are suggested in order to improve the ability of students when talking, thinking, reading and writing chemistry.

EVALUATION

Assessment of self-explaining effect in a large enrolment General Chemistry course

Adrián Villalta-Cerdas, Santiago Sandi-Ureña   115 - 125
[+]
Self-explaining refers to the generation of inferences about causal connections between objects and events for one’s own consumption. Self-explaining is amongst the practices of science deemed essential for scientific competence; therefore, a valued learning outcome in itself. Nonetheless, generation of authentic explanations is seldom promoted in college science instruction. This work examined the effect of engagement in self-explaining on conceptual understanding of chemistry. Learning and performance tasks were completed individually in the classroom ecology of a large-enrolment General Chemistry course in the US. The study spanned a period of five semesters including pilot-tests and replications. The self-explaining intervention followed a multi-condition comparison design that used performance on a post-test to assess learning. Students were randomly assigned to the following conditions: reviewing a correct explanation, explaining correct or incorrect answers, explaining agreement with answers produced by others, and explaining their own answers. A cohort of students who underwent standard instruction with no intervention and had prepared for formal examination served as reference. The self-explaining cohorts performed better than the reference group, and in one case was the difference statistically significant. Findings suggest that self-explaining activities support students’ conceptual understanding at least as much as instruction. This study contributes evidence for the self-explaining effect and the ICAP hypothesis in a discipline where no evidence is available. Furthermore, it adds to the relatively little work in self-explaining that has explored naturalistic learning environments. This work supports the incorporation of self-explaining activities in the repertoire of instructional practices for General Chemistry.

EVALUATION

Jerarquización de competencias genéricas basadas en las percepciones de docentes universitarios

Antonio Medina-Rivilla, Francisca Ofelia Muñoz-Osuna, Manuela Guillén-Lúgigo   126 - 132
[+]
In the educative context, the term competency is referred to an integration of knowledge, attitudes, and skills that allows the individual to successfully perform a set of functions. The generic competencies are those common to most professions that are transferable between different activities in one sector or organization. During the evaluation process, remains the need to know which ones are the competencies that teachers consider as fundamental. In order to identify the perception of the teachers about the hierarchy of desirable generic professional competencies, a questionnaire of 23 competencies was applied to 111 professors of the Department of Chemical and Biological Sciences (DCBC) of the University of Sonora (Mexico). This study showed a tendency to the development of competencies related to the learning processes andoriented towards a strong academic instruction. However, interpersonal competencies wereplaced on the last positions; this situation shows some weaknesses on the social component ofeducation.

HOW IT IS EXPERIMENTED?

Utilización del colorante índigo en el laboratorio docente de Química Orgánica

A. Vanessa Saura, Francisco Galindo   133 - 138
[+]
Indigo is one of the first examples of vat dyeing, being the reduction of the dye to its soluble form (leuco-indigo) the critical step of that process. A new method to address such reduction reaction has been tested which improves the overall results for the staining with this dye, at a didactic level in an Organic Chemistry laboratory practice. The innovation introduced consists of using a small sized round-bottom flask along with a balloon and a needle to release the inner overpressure. Compared to the traditional process, the new method allows for the reduction at lower temperatures (30 ◦C vs. 66 ◦C) and a more homogeneous fabric dyeing.

HOW IT IS EXPERIMENTED?

‘‘Green’’ Suzuki-Miyaura cross-coupling: An exciting mini-project for chemistry undergraduate students

Bruna Pereira Vargas,, Clarissa Helena Rosa, Diego da Silva Rosa, Gilber Ricardo Rosa   139 - 142
[+]
A three-week mini-project is described for an experimental Physical Chemistry or Organic Chemistry course. The activities include synthesis of a biphenyl (4-methoxybiphenyl) via the Suzuki-Miyaura cross-coupling reaction using an adapted domestic microwave oven. The technical skills and concepts that are typically presented in practical chemistry courses are covered, including microwave heating, separation of mixtures, TLC techniques, melting range determination, stoichiometric calculations, and GC---MS techniques.

TEACHERS' TRAINING

Pre-service secondary and High School teachers were asked to rank some chemistry tasks, considering the level of proximity to daily context and level of problematization, in order to analyse their view of contextualization and problematization. Their answ

Ana Belén Montoro-Medina, Yolanda Cortés-Galera, María Rut Jiménez-Liso, Francisco Gil-Cuadra   143 - 153
[+]
Pre-service secondary and High School teachers were asked to rank some chemistry tasks, considering the level of proximity to daily context and level of problematization, in order to analyse their view of contextualization and problematization. Their answers allow us to group them in clusters, and the analysis of their composition give us some characteristics of each profile: some of them think that all of the tasks were a problem and everyday tasks, others identify everyday problems with any material which doesn´t belong to a lab and problems any task which entails an action (measure, explain. . .). These profiles are of special relevance to teacher training to promote contextualization and scientific inquiry.

CHEMISTRY EDUCATION

Mark A. Griep, Marjorie L. Mikasen   154 - 162
[+]
To introduce more chemistry into a middle and high school bioengineering camp experience, we developed an educational and entertaining presentation that examines the chemistry in movies about aliens and minerals from outer space. Our goal was to help the campers to think creatively about the bioengineering projects they are doing and about its chemistry. After watching each movie clip, we explain whether the chemistry in the clip is real or fake, and then describe the real chemistry that inspired it. The chemical touchstone for the presentation is the periodic table. First, the campers learn that aliens in five movies are composed of the same elements as those found on Earth, although some do not have the same biochemistry. The second half of the talk is about the utility of extraterrestrial minerals of known composition. The campers learn that moviemakers speculate that people of the future might visit other celestial bodies to collect scarce minerals with known properties. The topics of alien biochemistry and extraterrestrial minerals are not often taught in the classroom. The pairing works well, however, for chemical outreach because it shows students how to bring divergent thoughts together to solve problems and, therefore, encourages creative chemical thinking.

TO TAKE THE DUST AWAY

Nicolas-Jean-Baptiste-Gaston Guibourt (1790-1867), un farmacéutico Francés; que investigó los óxidos, sulfuros, y otros compuestos del mercurio; el arsénico y sus compuestos, un gran número de productos naturales, entre ellos, trementina, almidón, jugos a

Jaime Wisniak   163 - 171
[+]
Nicolas-Jean-Baptiste-Gaston Guibourt (1790---1867), a French pharmacist, who studied the oxides, sulfides, and other compounds of mercury, arsenic and its compounds, a large number of natural products, among them turpentine, starch, astringent juices, and musk; also established the norm to express the power of pepsin.
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