Abstract: Prediction of aromatic and anti-aromatic behavior of organic compounds is a vitally important tool for students of chemistry at graduate and post-graduate level for solving different kinds of problems regarding reactivity, stability and acidic properties etc. In this manuscript we try to present a simple and innovative method for easy identification of aromatic and anti-aromatic behavior of organic compounds from their non-aromatic nature excluding Huckel’s rule of aromaticity.

Abstract: A simple and cost-effective bench-top gas generator for its use in the laboratory classes is designed and fabricated. The set-up is meant for generation of hydrogen sulfide gas and is in use by the students at the chemistry laboratory of our college for the past eight years. However, other gases like carbon dioxide, hydrogen and acetylene can also be produced using the same set-up. This article describes the design and fabrication of the bench-top set up with special reference to generation of hydrogen sulfide gas. The new set-up is easy to use and requires few chemicals.

Abstract: The strength of an acid is generally discussed as a unique feature of the acid itself according to its chemical structure. Strong acids have a lower pK_a value, and weak acids have a higher one. In the classrooms of high schools and universities, we sometimes use the technical terms “strong acid” and “weak acid”. However, there are some acids for which it is very difficult to say, from their pK_a values, whether they are strong or weak. This research addresses the distinction between strong acids and weak acids, in a restricted initial concentration of acids, to provide a clear distinction between strong acids and weak acids.

Abstract: Toxics metals have been excessively released into the environment due to rapid industrialization and have created a major global concern. Cadmium, zinc, copper, nickel, lead, mercury and chromium are often detected in industrial wastewaters. Various methods available in literature but due economical point view are facing difficulties to be adopted. Some alternative methods like adsorption material bagasse, rice husk, wheat husk sawdust etc, are more popular due to efficiency as well as cost of treatment. In present study bagasse from sugarcane industry were used to remove the toxic metal from waste. Batch studies were performed to evaluate the adsorption process, and it was found that the bagasse was found to adsorb 96.4% of Cadmium (II) and 93.8% of iron (II). The rate of adsorption follows pseudo-second-order kinetics before attaining equilibrium. The desorption studies suggested that the desorption of Cadmium (II) and iron (II) was the most difficult and the desorption was zero. This work proved that bagasse can be used as an efficient adsorbent material for removal of heavy metals from water and wastewater.

Abstract: Prediction of number of π-bonds, σ-bonds, single and triple bonds of aliphatic unsaturated open chain and cycloalkynes is a vitally important tool for students of chemistry at undergraduate and graduate level for solving different kinds of problems regarding different chemical reactions. In this manuscript, we try to present a simple and innovative method for easy calculation of number of π-bonds, σ-bonds, single and triple bonds with the help of completely 8 (eight) new formulae.

Abstract: The textbook followed by freshmen engineering students (at least in reputed universities of India), is “Elements of Physical Chemistry,” by Peter Atkins and Julio de Paula. Considerable amount of chemical kinetics is dealt in this book, but negative order and fractional orders, which are fundamental for the complete comprehension of chemical kinetics, are not dealt conceptually in this book. The same is the case with other standard text books meant for freshmen undergraduate students. Many a time, even after grappling with complex problems in accounting of rate laws, students do not understand the precise conceptual meaning of these terms. The conspicuous absence of conceptual explanations of these terms in the freshmen text books has prompted us to write this article. The authors are of the opinion that, after going through this article one would definitely feel that, this article is a silver bullet for the conceptual comprehension of the terms negative order and fractional orders in the field of chemical kinetics.

Abstract: For any titration, the titration error is, by definition, the difference between the volume of titrant added to reach the end point and the volume of titrant necessary to reach a stoichiometrically defined equivalent point. A graphical approach is presented, which allows a smooth and far reaching quantitative discussion of the systematic titration error of Acid-Base titrations, on the basis of the Logarithmic Acid-Base Diagram representing the titrated solution. Considerations and relations are developed which connect this diagram to the titration error. Examples are fully developed, which show that the procedure suggested unavoidably goes beyond the technical or practical topic of evaluating the systematic titration error, and it can be especially rewarding from an educational point of view. Finally, for the reader’s convenience, algebraic expressions and brief instructions to draw Logarithmic Acid-Base Diagrams (also known as Sillén’s diagrams), by using a spreadsheet, are provided.

Abstract: Chemistry programs at universities include oxidation-reduction (redox) reactions. Based on particular examples the article shows the possibility of application of electromotive force (EMF) calculation to evaluate the possibility for redox reactions to take place and to justify the experimental data. The standard potentials are used for the calculation of EMF of redox processes according to the formula , However, the standard conditions differ from the conditions under which the real experiment is carried out. Therefore, instead of the standard potentials the author of the paper suggests to use stationary metal potentials which have proved them in practice. The formula for calculation of EMF is replaced by the modified formulas: when metals are dissolving in acids and bases ;in case of galvanic cells and corrosion . These modified formulas enable more real and precise calculation of EMF of redox processes, what is proved by the provided examples.

Abstract: A typical kinetic experiment, the persulfate–iodide clock reaction, is selected as an example to illustrate applications of thermodynamic possibility and kinetic actuality in chemical reactions. In the experiment, the strongest reducer, sodium thiosulfate Na₂S₂O_3, cannot be directly oxidized by the strongest oxidizer ammonium persulfate (NH₄)₂S₂O₈, and this redox must be realized by an intermediate iodine I₂ [presenting in I₃^- anion, a weaker oxidizer than (NH₄)₂S₂O₈]. After I₂ molecules being reduced by Na₂S₂O₃ molecules to form I^- ions (a weaker reducer than S₂O₃^2-), the strongest oxidizer begins to oxidize the weaker reducer I^- ions to form I₂ molecules again, which is keeping on the redox circles until the stronger reducer Na₂S₂O₃ has been exhausted completely. Why the strongest reducer was not being oxidized by the strongest oxidizer? In this paper we attempt to explain this situation based on the chemical theories of thermodynamics and kinetics.

Abstract: Context based learning approaches have been presented in this article as a way to enhance student’s interest in, as well as time economic learning outcomes from chemical education. In this article 16 years research based time economic study has been presented on hydrocarbon, aromaticity and chemical bonding to cultivate the interest of teaching and learning in organic and inorganic chemistry when solving context-based chemistry problems. In this pedagogical survey, we have tried to hub twelve (12) innovative and time economic methodologies by including thirty two (32) completely new formulae in the field of Chemical Education. Concepts that usually confuse the students in the examination hall have been explained here by some innovative methods based on applied mathematics. In this context, current trends in chemistry have been highlighted by some technical methods. The review explores the results and gives implications for context-based teaching, learning and assessment.