1. Redox Catalyst Catalyst is defined as a substance that increases the rate of a chemical reaction without changing its chemical composition and affecting the standard Gibbs free energy, by lowering the activation energy of a chemical reaction. It does so by providing an alternative reaction pathway. In redox reaction, the key chemical event is the net movement of electrons from one reactant to the other. The oxidation state of atoms are changed. Transition metal is used as redox catalyst due…
Demitri Mendeleeve was a Russian chemist who invented the first periodic table in 1869. The periodic table he made was very different from the modern day periodic table we know today. Henry Moseley updated Mendeleev's version of the periodic table in 1915. This is more like the periodic table that we know and use today. The only difference is that there has been many more elements added. Mendeleeve also had predicted a lot of the characteristics and properties of elements that would fill up…
1. Chemical reactions involved in the oxidation of benzene (adapted from Lupușor et al., 1981) In order to achieve such an analysis, a simplified mathematical model of the reactor was used considering a pseudo-homogeneous, one-dimensional, plug-flow reactor. Model equations are presented in the Table 1 in terms of the mass balance of the considered chemical species, heat and moment balance, with the rate constants given in Table…
3.1. Chemical composition and monosaccharide analysis Polysaccharide molecules are linked together by water molecules through hydrogen bonds in an aqueous solution. Adding ethanol into aqueous solution of polysaccharide initially dehydrate polysaccharides, enhance intra-molecular hydrogen bonding, cause conformational change and aggregation of polysaccharide molecules, and eventually leads to the precipitation of macromolecular chains, and the following addition of alcohol solvent gradually…
In this model no any chemical reaction is considered.(Barba et al.) modelled gasification by considering it to occur in two steps, in the first of which the biomass is decomposed at high temperature to give primary gas and carbonaceous residue and in the second there is modification…
The purpose of this study was to investigate the effect of a system that automatically adjusting hydrogen peroxıde Colloıdal-Ag dose to reduce colonization and growth of heterotrophic bacteria in dental unit waterlines and wastewaters. Thirty dental units were assigned into three groups with respect to the protocol employed: Group 1: 10 units were selected for automatic administration. Group 2: 10 units were selected for manual administration and Group 3: 10 units served as controls. Water…
3.6 Sorption isotherms The experimental adsorption equilibrium data were analyzed using Langmuir, Freundlich, Temkin and D-R isotherms. The sorption data was analyzed using linear form of all the isotherm equations Models having high correlation coefficient (R2 ) values are considered best fit to represent the sorption data. The Freundlich isotherm holds for multilayer non-ideal adsorption on heterogeneous surface and is represented by the following empirical equation: qe = KF Ce 1/n Where,…
1 enzyme Enzymes are biological catalysts. A protein compound Energy can reduce the carbon reaction. Enzymes to accelerate specific types of reactions. And the kind of substance that reacts. 2.1.1 catalysis of enzymes E is a catalyst (enzyme). S is a precursor called chop, nitrates and substance P is a product. E + S ---------------> E S ---------------> E + P. Complexometry 2.1.2 Factors affecting the enzyme. 1) What type of controlled…
recently, Pcs have found high-tech applications in electrophotography and ink-jet printing and as photoconducting agents in photocopying devices. In addition, their novelty is rapidly growing in other fields where they are used as sensing elements in chemical sensors, electrocatalysts, liquid crystals, electrochromic display devices, information storage systems, semiconductors, functional polymers and molecular metals, among others. They have also found use in photodynamic therapy (PDT).…
Batch adsorption experiments Adsorption of the Pb2+ ions by the Fe3O4@GMA-AAm nanocomposite was measured from batch adsorption experiments by mixing 10 mg of adsorbent with an aqueous solution containing a predetermined concentration of Pb2+ ions (50 mL). The mixture was shaken at 200 rpm to reach equilibrium. After a specified time, the solid and liquid were separated by external magnet and the concentrations of Pb2+ ions were measured by AAS. To find the optimized pH in adsorption of Pb2+ ions…