SiO2 is often found in quartz and it has a series of polymorphs other than the amorphous forms. The Si-O-Si angle can vary between 140° in α- tridymite to 180° in β-tridymite. Crystal Structure of Quartz Crystal structure of FePO4 Paragraph 2 Illustrate and describe the symmetrical differences between α-FePO4 and β- FePO4. α-Fe in α-FePO4 has this body-centered cubic B.C.C crystal structure and it is this crystalline structure which allows steel and cast iron to possess their magnetic properties. α-Fe in α-FePO4 has a strength of 280 N/mm and also a hardness of approximately 80 Brinell.
Each metallic bond has a general structure of metal ions and an electron cloud which has occurred due to the sea of valance electrons. This can be seen below in Figure 4. These free electrons are the reason metals are such good electric and thermal conductors. As there is different strength in the bonds the melting and boiling points vary according to this. The strength of the metals also varies based on the strength of the bond.
Production diclofenac acid (DFA) by diclofenac sodium (DFS) hydrolysis DFA which yielded from DFS hydrolysis was characterized by FT-IR and DTA. Fig. 2 showed the information provided by the spectra FT-IR profile, which distinguished DFS from DFA. The DFA’s spectra showed a specific absorption peak at 3324 cm-1 which correspond to free OH stretching of a carboxylic group. Free acid was also presented as a peak at 1693 cm-1 associated with C=O stretch and 1157 cm-1 correspond to the C-O stretch.
Typically, modern chemists make use of Atomic Absorption Spectroscopy to determine, quantitatively, the concentration of small and often trace elements found within certain substances and/or the environment. such measurements can be made due to the sensitive nature of AAS, as measurements that are taken can be into the parts per million (ppm). In principle, AAS works, by using ground state atoms. (which are atoms that have the lowest possible shell orbit to the nucleus due to containing very little energy). (see bibliography: Smith, R. (2010).
It is not applicable to grains larger than about 0.1 to 0.2 μm, which precludes those observed in most metallographic and ceramographic microstructures.It is important to realize that the Scherrer formula provides a lower bound on the particle size. The reason for this is that a diversity of factors can contribute to the width of a diffraction peak besides influential effects and crystallite size; the most important of these are customarily inhomogeneous strain and crystal lattice imperfections. The following sources of peak broadening are listed in reference. dislocations, stacking faults, twinning, microstresses, grain boundaries, sub-boundaries, coherency strain, chemical heterogeneities, and crystallite smallness. If all of these other contributions to the peak width were zero, then the peak width would be determined solely by the crystallite size and the Scherrer formula would apply.
This phase is one of the important Aurivillius oxides  possessing special perovskite-like layer structures, photocatalytic activity under visible light irradiation, the increased optical absorption efﬁciency and the decreased photo-generated carriers recombination efﬁciency. The FTIR spectra provided structural information as the arrangement of the structural units present in the glass samples with
The appropriate combination of dissociation of the components due to the addition of the second component, the existence of weak forces between unlike molecules and differences in sizes and shapes of the components affects the sign and magnitude of the excess isentropic compressibilities . The values in liquid mixtures depends on the molecular structure of component liquids, and influenced by other factors like dipole-dipole interactions, hydrogen bonding, and charge transfer interactions and or complex formation. An examination of data in Table 4 cause that the factors causes for negative excess isentropic compressibilities were dominant in the binary mixtures of N-methylformamide with ketones at (303.15 to 318.15) K. The observed negative values indicate that dipole-dipole interaction between unlike molecules is stronger than N-methylformamide- N-methylformamide or ketone-ketone interactions in all the systems under study . The algebraic values fall in the order cyclopentanone > cyclohexanone >
The cis and trans isomers are diastereomers of one another. Therefore, in this experiment the product was determined by assessing the melting points of the compound and comparing it to the known value. Isomers are a molecule that contains the same molecular formula as another molecule but differs in their chemical
They can impart localised structural rigidity, confer cytotoxicity by alkylation, or be secondary metabolites . The chemistry of epoxides is dominated by the reactions that involve opening of the strained three-membered heterocyclic ring by nucleophiles. Such reactions yield valuable bifunctional compounds. In nature, epoxide ring opening is catalysed by the phenolic proton of a tyrosine moiety . But in laboratory, the cleavage usually occurs in non-aqueous media in presence of a Lewis acid catalyst like Al2O3, Li+, Mg2+ etc.
Properties of Ionic and Covalent Substances Lab Report Introduction The purpose of this lab was to determine which of the following substances: wax, sugar, and salt, are an ionic compound and which are a covalent compound. In order to accurately digest the experiments results, definitions of each relating factor were researched, leading to the following information: ionic compounds are positive and negatively charged ions that experience attraction to each other and pull together in a cluster of ionic bonds; they are the strongest compound, are separated in high temperatures, and can be separated by polar water molecules. A covalent compound is formed when two or more nonmetal atoms share valence electrons; covalent compounds are also categorized into two sections: polar covalent and nonpolar covalent. Furthermore, polar covalent compounds dissolve in water, while nonpolar covalent compounds do not. Dissolving is the process in which a solvent and a solute interact with each other and form a solution.