by Ya Hong Wu, Shan Ling Tong, Sheng Hu, Mao Ying Wu, Zhi Feng Hao and Yan Yan
Opinion Paper
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 Na2S2O3, 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 S2O32-), 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.sex stories moms escort service reader
click marriage counselor joke classic adult jokes jokes stories humor funny
walgreens photo coupons in store
link prescription discount cards
walgreens photo print coupon
open coupon for medication
zovirax
site levofloxacin 500mg
neurontin 400mg
site zovirax pill
can i take naproxen with prednisone
link can i take naproxen with prednisone
World Journal of Chemical Education. 2014, 2(2), 26-28. DOI: 10.12691/wjce-2-2-2
Pub. Date: June 23, 2014
17200 Views6756 Downloads35 Likes
by Algirdas Sulcius
Original Research
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.tracking app for android
go free spyware app
World Journal of Chemical Education. 2014, 2(2), 21-25. DOI: 10.12691/wjce-2-2-1
Pub. Date: June 05, 2014
21110 Views5667 Downloads41 Likes