Volume 14, Issue 4 (2005)
| 41st National Conference
of the Bulgarian Teachers in Chemistry. Part I. |
247 |
| Authors: A. Antonova; M. Bencheva,
L. Boyanova, H. Kalpachka, N. Encheva, I. Ivanov, S. Tsakovski and A. Mutafov; E.
Boyadzhieva, M. Kirova and S. Manev; L. Boyanova and M. Bencheva; L. Boyanova; A.
Gendzhova and L. Boyanova; A. Gendzhova and L. Boyanova; L. Genkova and V. Naydenova; E.
Gergova and J. Dimova; E. Gergova and L. Popov; V. Dimitrova; V. Dimitrova, S. Manev and
I. Manolov; R. Draganova-Hristova; N. Encheva, L. Boyanova and B. Zheliazkova; V.
Filipova, K. Dimitrov and D. Mitev; H. Kalpachka and B. Radoev. |
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Full text: PDF (126 KB) |
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| Teaching Chemical
Experiment: |
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| V.M. Petrusevski,
M. Monkovic. Exothermic Processes: Quite Oxidation of NO by Oxygen - A Lecture
Demonstration |
362 |
Full text: PDF (224 KB) |
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| Foreign Educational
Tradition: |
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| D.S. Mahajan, G.S.
Singh. Chemistry Education in Botswana: Towards Realization of Vision 2016 |
367 |
Full text: PDF (196 KB) |
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| Advanced Chemistry: |
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| H.R. Pouretedal, A.
Semnani, M.H. Keshavarz, A. Firooz. Spectrophotometric Study of the Interaction between
Iodine, Iodine Monochloride and Bromine with 1,3,5-Trithiane in Chloroform Solution |
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Khimiya, Volume 14, Issue 4 (2005)
Khimiya. 14, 362-366
(2005):
Abstract. Processes of
vigorous oxidation are well known to be exothermic, as evidenced be common experience. It
could be proved that processes of quite oxidation (rusting of iron and breathing are only
two of the many examples) are also exothermic. In the offered demonstration, oxidation of
nitric oxide (NO) with pure oxygen is monitored via thermocouple thermometer in a reaction
chamber. Temperature increases by more than 15 oC, thus proving that this is
another example of quite (yet instantaneous) oxidation.
References: 8
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Khimiya. 14,
367-374 (2005):
Abstract. Botswana is an independent sovereign nation
situated in Southern Africa. The nation has recently adopted the policy document “Vision
2016” for its long-term development. All sectors of the country are in process of
formulating policies and implementing them to reach the goals, described in this document,
by year 2016, the 50th year of the country independence. Major changes have
already been taken place in education sector both at secondary and tertiary levels. Both
curricula and assessment systems have been reviewed recently. The article gives an
overview of the educational system and the current status of chemistry education in Botswana.
References: 8
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Khimiya. 14,
375- 384 (2005):
Abstract. The interaction
between iodine, iodine monochloride and bromine as s-acceptor and 1,3,5-trithiane as
n-donor has been studied spectrophotometrically in chloroform solution at 25 oC.
The results of iodine indicate the formation of complexes [trithianeI+I3-]
and [trithianeI+I-] in the low and high trithiane/iodine mol ratios,
respectively. These adducts are formed through equilibrium reactions. In the case of
iodine monochloride, the 1:4 trithiane to ICl mole ratios and the simultaneous realization
of iodine and (ICl)2Cl- through two-equilibrium reactions are
confirmed. The possible reactions which produce adducts species are suggested. A
bathochromic shift and an increase in the intensity of bromine band through nonequilibrium
reaction have been observed in the case of bromine. These observations have been
attributed to the partial charge transfer from trithiane to antibonding orbital of
bromine. The conductivity measurements indicate that all donor-acceptor adducts are in the
form of ion pair. Finally, all of the experiments were repeated at 40 oC and
except of curvature of absorbance-mole ratio plots, similar results were obtained.
References: 35
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