Сп. „Химия“, книжка 4/2010

Editorial

Intelligence and Literacy

Резюме. The intelligence is an inherent property of all beings. Only the human beings have a language. The information must be obtained and exchanged by the language. The successful man (in life and work) should transform more and more information. Only a school could make the man to be educated. The paper considers a great number of related questions: intelligence (what does it mean), literacy (what does it mean), education, contemporary school, the influence of ICT (information and communication technologies) on the modern man. Some problems of the educational reforms in Bulgaria are discussed as well.
Keywords: intelligence, literacy, schooling, ICT

B.V. Toshev

Letters to the Editor

To Enhance Pupils’ Interest to Chemistry by Discussing of a Preliminary Read Book

Z. Garova

Teaching Efficiency

Use of Students Portfolio in Teaching and Learning Chemistry

Резюме. The article shares authors’ experience in using student portfolio as a part of the school (National Natural Sciences and Mathematics School in Sofia) system for control and evaluation pupils’ achievements in the subject of Chemistry and Environment. The special topic considered is the solutions of electrolytes. The article presents also the basic instructive materials being a part of the final product.
Keywords: students’ portfolio, solutions, electrolytes

A. Ilieva, D. Dimova

Teaching Efficiency

Application of the Constructivist Approach in Teaching and Learning Chemistry

Резюме. A research has been conducted on the influence of application of constructivist approach in teaching chemistry on students from 10th grade and more specifically the strategy of Slavin (2005). The author uses this strategy to teach lesson for assimilation of the concept “isomerism”, as well as for development of positive attitude of learners to chemistry as a subject. In the research are included 27 students from two classes (science profile and social science profile), to whom the subject “Chemistry and environmental protection” is taught in English by the same teacher.
Keywords: chemistry teaching, constructivism, Slavin’s strategy, isomerism, students’ attitude to chemistry

I. Emilov

Reviews

Mendeleev and the Periodic Table

Резюме. The recent book by Eric R. Scerri deals with the history and development of Mendeleev’s periodic table. The book consists of 10 chapters. The first five chapters analyze the classical view on the periodicity of the chemical elements. A separate chapter concerns Mendeleev alone with carefully chosen important (some unknown) biographical details. The remaining five chapters describe the modern point of view on the periodicity of the chemical elements: radioactivity, isotopy, elements transmutation, quantum mechanical interpretation of the chemical elements periodicity and even the possible projections to astrophysics are amongst the topics considered in this part of the book. “The Periodic Table“ is an excellent book which could be used both by the professional chemists and chemistry students as well.
In Bulgaria Mendeleev and Lomonosov are most popular among Russian scientists. However, books and articles about Mendeleev, published in Bulgaria, most are rather propaganda, than science or history of science. So Scerri’s book could successfully fill this gap. The present review is a good reason to mention the only Bulgarian scientific article on the periodic law (Balarew, 1950). The review also gives more information about the rearrangement of the Bulgarian chemical school literature on the basis of the periodic law in the late nineteenth-century. Finally, Russian sources from 1907 are used to give an idea about the appreciation of Mendeleev’s work in the then Russian society.
Keywords: Mendeleev, Scerri, periodic table

B.V. Toshev

Curriculum Matters

Achievements in Chemistry of Students (10. Grade) from Different Types of Secondary Schools

Резюме. National educational content standards are supposed to provide an equality of the school education for the different types of schools. The present study aims at the evaluation of the 10th grade student achievements of the State educational requirements in Chemistry and Environment school subject according to the type of the school. 1009 10th grade students attending four types of Bulgarian secondary schools: bilingual, natural-mathematical sciences, vocational and general participate in this study. The achievements are measured by a test, which is focused on the intended outcomes as they described in the statutory content standards. The results reveal a significant difference between specialized schools of foreign languages and natural-mathematical sciences, on the one hand, and vocational and general schools, on the other hand. These findings are in accordance with those of recent international studies, such as PISA. Similar studies in other school subjects would be of benefit to develop clear and rigorous content core standards and to serve as а hallmark of the standards-based reform in Bulgaria.
Keywords: secondary education, chemistry education, educational standards, stanrd-based approach

E. Boiadjieva, M. Kirova, A. Tafrova-Grigorova

Chemistry & History of Chemistry: An Online Supplement

Kinetic Experiments in the Undergraduate Chemistry Laboratory – Mistakes and Measures: Acid Catalyzed Hydrolysis of Methyl Acetate as an Example

Резюме. Kinetic study of acid catalyzed hydrolysis of methyl acetate is described
in detail for undergraduate laboratory students. Identification and rectification
of frequently encountered mistakes in this experiment are discussed.
Keywords: kinetics, hydrolysis of methyl acetate, first order reaction

V. Jagannadham

Chemistry & History of Chemistry: An Online Supplement

Inquiry-Based Experiment on the Synthesis of K3[Fe(C2O4)3].3H2O

Резюме. In the present paper inquiry-based learning strategy applied to the
laboratory work (inquiry-based labs) was used to synthesize and characterize the
potassium ferrioxalate complex. The implemented educational strategy showed to be an excellent methodology to develop experimental activities of inorganic chemistry. In this work the synthesized compound was identified and characterized by infrared spectroscopy, X-ray diffraction, magnetic susceptibility and photosensitivity under UV/Vis irradiation. The experimental procedures were explored and implemented by the students, under orientation and inspection of the teacher. The students showed their abilities to formulate „scientific questions“ and hypotheses, search scientific literature and write and discuss scientific results, which constitutes an excellent exercise about the experimental science construction.
Keywords: chemical education, inquiry-based experiment, synthesis of inorganic compounds, potassium ferrooxalate

J.C. Carriazo

Chemistry & History of Chemistry: An Online Supplement

Thermodynamic Study of the Diclofenac Sodium Solubility in Various Oils

Резюме. Diclofenac sodium is sodium salt of [o-(2,6-dichloro aniline) phenyl] acetate and is a potent non-steroidal anti-inflammatory drug (NSAID). In the present
communication, the thermodynamic study of diclofenac sodium solubilization in various oils like olive oil, castor oil, arachis oil, sunflower oil, soybean oil and liquid paraffin was investigated. Diclofenac sodium was found to have the increasing solubility and partition coefficient with the temperature rise in various oils used in this investigation. The maximum solubility and partition coefficient were found in case of castor oil, while these were minimum in case of liquid paraffin at various temperatures. Diclofenac sodium solubilization in all these oils, used in this investigation was found to be endothermic process. The valuable data obtained from this investigation can be utilized for designing and development of various oil based formulations of diclofenac sodium.
Keywords: diclofenac sodium, solubilization, partition coefficient, thermodynamics

A.K. Nayak

Свързани статии:

Сп. „Химия“, книжка 1/2010 Сп. „Химия“, книжка 2/2010 Сп. „Химия“, книжка 3/2010 Сп. „Химия“, книжка 5/2010