Zewdu Gebeyehu

• Columbus State University

A gravimetric method for the quantitative assessment of the products of electrolysis of water is presented. In this approach, the electrolysis cell was directly powered by 9 V batteries. Prior to electrolysis, a known amount of potassium hydrogen phthalate (KHP) was added to the cathode compartment, and an excess amount of KHCO 3 was added to the a...

An undergraduate laboratory experiment for the volumetric quantitative analysis of ascorbic acid and iron in dietary supplement tablets is presented. Powdered samples of the dietary supplement tablets were volumetrically titrated against electrolytically generated reagents, and the mass of dietary reagent in the tablet was determined from the volum...

We have studied electrophoretic deposition of AlN from its suspension in acetylacetone with I2 as an additive. AlN powder with particle size <10 μm is dispersed to produce a positive charge and deposited on the cathode by applying fields greater than 10 V/cm between the electrodes. X-ray diffraction and FTIR studies indicate that the AlN before and...

A directed study for the undergraduate physical chemistry laboratory for determining the transference number of H+(aq) using a modified moving boundary method is presented. The laboratory study combines Faraday’s laws of electrolysis with mole ratios and the perfect gas equation. The volume of hydrogen gas produced at the cathode is monitored and t...

A simple 3-h physical chemistry undergraduate experiment for the quantitative analysis of acetic acid in household vinegar is presented. The laboratory experiment combines titration concept with electrolysis and an application of the gas laws. A vinegar sample was placed in the cathode compartment of the electrolysis cell. Electrolysis of water gen...

An undergraduate experiment on coulometric analysis of four commercial household products is presented. A special type of coulometry cell made of polydimethylsiloxane (PDMS) polymer is utilized. The PDMS cell consists of multiple analyte compartments and an internal network of salt bridges. Experimental procedure for the analysis of the acid in a t...

We have synthesized several metal xanthate complexes from metal salts and xanthate potassium salts. Powders of several of the materials were sorted and tested for their nonlinear optical properties. Cadmium xanthate demonstrated phase matchability for frequency doubling of 1.06 micron light and generated a very strong second harmonic signal. How t...

Nutrient run-off and siltation are the main cause of non-point source pollution (NPSP) in US waterways. EPA has set a total maximum daily load (TMDL) of nutrient concentration in a given body of water and watershed approach to reduce NPSP. This study develops a model that integrates land use pattern and nutrient concentration in the creeks that dra...

The crystal structure of bis(O-isopropyl dithiocarbonato-S)cadmium(II), [Cd(C4H7OS2)2], has been determined by X-ray crystallography. The crystals are orthorhombic (space group Aba2). The coordination about cadmium is distorted tetrahedral.

Organoosmium(VI) complexes of PMe(3), PPh(3), and Ph(2)PCH(2)CH(2)PPh(2) (dppe) have been prepared and characterized. Unlike inorganic complexes of nitridoosmium(VI), the alkyl complexes are not reduced by basic phosphines. The reactions of [NBu(4)] [Os(N)(CH(2)SiMe(3))(4)] with HBF4 in the presence of either PMe(3) or PPh(3) produces Os(N)(CH2- Si...

The anionic organoosmium complexes [Y][Os(N)R(2)Cl(2)] (Y = PPh(4), NBu(4); R = CH3, CH(2)SiMe(3)) reacted with. (NH4)(2)WS4 or (NH4)(2)MoS4 to give the heterobimetallic complexes [Y] [Os(N)R(2)(mu-S)(2)MS(2)] (M = W, Mo). The reaction of [Os(N) (CH(2)SiMe(3))(2)Cl](2) with an excess of (NH4)(2)WS4 in CH2Cl2 at room temperature produced a trimetall...

Die Umsetzungen von MoNCl 3 bzw. WNCl 3 mit Lithium‐Diphenylamid in Tetrahydrofuran führen zu den monomeren Nitridokomplexen MN(NPh 2 ) 3 mit KZ = 4 an den Metallatomen. Bei Anwesenheit von Lithium‐n‐butyl reagiert LiNPh 2 mit WNCl 3 auch zu dem tetrameren, Wolfram(V) und Wolfram(VI) enthaltenden Nitridokomplex [W 4 N 4 (NPh 2 ) 6 (O ⁿ C 4 H 9 ) 2...