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The transition temperature between α phase and the β phase for FePO4 is 980K. When the temperature is low, which is below 980K, FePO4 is known to be in α phase. During α phase, it adopts a tetrahedral lattice structure with PO43- atom in the middle. When the temperature is high, which is above 980K, FePO4 is known to be in the β phase. As the temperature differentiates the phases of FePO4, the bridging angle and the tilt angle between the atoms in the lattice structure differs as well. As a result, the symmetry space group of FePO4 for both the α phase and the β phase will be different. At a low temperature of 294K, which is the α phase of FePO4, the symmetry space group is “P3121”. At a high temperature of 1073K, which is the β phase of FePO4, the symmetry space group is “P6422”. From the perspective of α phase for FePO4, it has 3 positions in the space group, with 1 general position and 2 special positions. On the other hand, the β phase of FePO4 has 11 positions in the space group, with 1 general position and 11 special positions. This shows that as the temperature increases, the number of general position remains constant, but the number of special positions
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As temperature increases, the bond distance in FePO4 decreases in length, which resulted in the decrease in the bridging angle between the bonds. This also indirectly increases the volume and the unit cell size. An explicit example will be tetrahedral Fe-O, where bond distances fall from 1.858(2) to 1.818(9) when the temperature increases from 294K to 969K, and subsequently decrease the angle of Fe-O as well. The bond distance falls lower to 1.73(2) when the temperature rises to the range of the β phase of 1073K. This summarizes the point that volumetric is dependent on the temperature, which is influenced by the bridging
Physical Chemistry Laboratory Manual, Physical Chemistry Laboratory, Department of Chemistry, University of Kentucky, Spring 2006.
This is an experimental lab that tested if drinking water passes the United States maximum phosphate standard. The results of this lab can help the American who drink the water know if there are too much phosphate in the water. Each group made a Potassium phosphate dilution from a stock solution. The concentration of the solution that needed to made affected the amount of Potassium phosphate that was diluted. To create a calibration curve, each group used the different concentrated Potassium phosphate solutions in their test. The lab utilized a spectrophotometer to figure out the absorbance of the five different Potassium phosphate solution and the absorbance of an unknown concentration solution. The absorbance of the unknown solution was used
The purpose of conducting an experiment using various temperatures, pH levels, and enzyme concentrations was to observe the effects these factors had on the rate of horseradish peroxidase activity. Furthermore, testing how peroxidase reacts to different set ambient conditions and finding the conditions that allow for maximum rates. Enzymes are used in this experiment to demonstrate the importance of certain environmental conditions since they affect the speed of an enzymatic reaction in order to carry out life. An extract from horseradish is used as the enzyme since it contains peroxidase which has a highly accessible active site. The experiment was administered by using a spectrometer as a tool to measure oxygen production using an indicator called guaiacol which would allow the rate of horseradish peroxidase activity to be seen. Environmental circumstances, such as enzyme concentration, temperature, and pH, are tested by using guaiacol as an indicator of oxygen production and H2O2 as an oxygen producing agent. The ending results conclude that higher enzyme concentration can increase the speed of the rate of enzyme activity. The results also conclude
In this experiment, an acid (Benzoic acid), a base (Ethyl 4- Aminobenzoate) and a neutral compound (9-Fluorenone) were extracted from a mixture. HCl was the acid used to separate the base from the mixture, by forming an organic layer, which contained the acid, the neutral compound, and an aqueous layer that contained the base. NaOH was the base that was used to separate the acid from the neutral compound, which resulted in an organic layer containing the neutral compound and an aqueous layer containing the acid. After this a base was then added to the first aqueous layer containing the base, and an acid added to the second aqueous layer containing the acid. The percent recovery of each compound was then evaluated. The basic component, Ethyl
middle of paper ... ... Chemistry, the Central Science 11th Edition (p. 1072). (2009). The 'Standard' of the 'Standard'. 25.
The isomerization procedure was done in order to create dimethyl fumarate from dimethyl maleate. Dimethyl maleate and dimethyl fumarate are cis and trans isomers, respectively. This procedure was done via a free radical mechanism using bromine. The analysis of carvones reaction was done in order to identify the smell and optical rotation of the carvone samples that were provided. The odor was determined by smelling the compound and the optical rotation was determined using a polarimeter.
The molar specific heats of most solids at room temperature and above are nearly constant, in agreement with the Law of Dulong and Petit. At lower temperatures the specific heats drop as quantum processes become significant. The Einstein-Debye model of specific heat describes the low temperature behavior.
• The use of a catalyst will speed up the reaction as long as the catalysts electrode potentials are feasible for each step in the reaction. Since a catalyst lowers the activation energy and takes the reaction through a different route, according to the Maxwell-Boltzmann diagram, at a constant temperature more particles are able to react as demonstrated by the diagrams below:
23. S. Alwarappan, S. Boyapalle, A. Kumar, C.-Z. Li and S. Mohapatra, J. Phys. Chem. C, 2012, 116, 6556–6559
Iron comes from the Latin word ferrum. The iron’s symbol on the periodic table is “Fe”, driven from its Latin name. Iron has an atomic number 26, and an atomic weight of 55.847. Iron is a metal that is grayish metallic and magnetic. This element is classified as a transition element because it is both malleable and ductile, and it can also conduct heat and electricity. Iron, cobalt and nickel are the only elements in the transition metals family known to produce a magnetic field. Iron is relatively soft and a good conductor of heat and electricity (chemicool, 2014).Pure iron melts at about 1535 degrees Celsius. Its boiling point is at 2750 degrees Celsius. Iron has 26 electrons, 26 protons and 30 Neut...
is impossible to specify a single best method to carry out a given analysis in
Magnetic anisotropy is defined as the directional dependence of the magnetic properties for materials. Strong easy-axis anisotropy is a prerequisite for hard magnetism while near-zero anisotropy is desirable for soft magnets. Generally, the tendency for magnetization to lie along an easy axis is represented by the energy density
Ionic compounds, when in the solid state, can be described as ionic lattices whose shapes are dictated by the need to place oppositely charged ions close to each other and similarly charged ions as far apart as possible. Though there is some structural diversity in ionic compounds, covalent compounds present us with a world of structural possibilities. From simple linear molecules like H2 to complex chains of atoms like butane (CH3CH2CH2CH3), covalent molecules can take on many shapes. To help decide which shape a polyatomic molecule might prefer we will use Valence Shell Electron Pair Repulsion theory (VSEPR). VSEPR states that electrons like to stay as far away from one another as possible to provide the lowest energy (i.e. most stable) structure for any bonding arrangement. In this way, VSEPR is a powerful tool for predicting the geometries of covalent molecules.
Fig. 4 shows the magnetic hysteresis curve of γ-Fe2O3 nanoparticles observed at room temperature. Magnetization curves of the nanoparticles were measured at 10,000 gauss. The development of saturated loop confirms the magnetic nature of the sample. The small value of hysteresis and remnant magnetization which can be neglected indicates that these particles are superparamagnetism in nature. The typical characteristic of the superparamagnetic behavior in the magnetization curve showed very small coercivity (~131.66 gauss) and remanance (~1.46emu/g). A saturation magnetization of ~13.4 emu/g was determined for the fine γ-Fe2O3 particles.
Femicide is defined as the act of killing a female simply because she is female. Acts of femicide includes “honor killings,” “dowry deaths,” genital mutilation, rape in war and victimization o female refugees. The treatment of women prisoners and detained immigrant women are also related to the issue of femicide. Essentially, femicide is a form of gender-based violence (Stuart van Wormer & Bartollas, 2011). It is considered to be an extreme form of gender-based violence that may include torture, mutilation, cruelty and sexual violence. The violence often culminated to murder. This violence is linked to gender concepts like inequality, discrimination and disempowerment (Femicide, 2008). It is also viewed as “a form of terrorism that functions to define gender lines, enact and bolster male dominance, and to render women chronically and profoundly unsafe” (Suarez, 2009). Based on international federal and state law, women have the right to be free from violence. Overall, acts of femecide are viewed as a violation of the human rights of women (Femicide, 2008).