Hydrogen bond

The Calorimetric Determination of Enthalpy and Entropy Changes of the Thermal Decomposition of Sodium Sulphate Decahydrate Abstract Sodium sulphate decahydrate thermally decomposes to anhydrous sodium sulphate at 50⁰ C and cools to form anhydrous sodium sulphate. Using Hess's Law the enthalpy and entropy changes of this process can be determined in order to deduce the spontaneity of the reaction. The transition temperature was determined by melting the hydrated crystals at 50⁰ C and allowing…

The experiment is an investigation about the Zeeman Effect in an atomic Cadmium lamp. The part of the spectrum observed will be the 645nm (red) emission line. Electrons occupy energy levels within an atom when a photon of energy hf is absorbed by an electron in the n=1 level and if the energy is such that the electron is excited and ascends to the n=2 level after some time the electron will then descend back to the n=1 level and a photon of hf will then be emitted again. Each atom has its own…

Haines et al., A neutron diffraction study of quartz-type FePO4: high-temperature behavior and αβ phase transition Kristallogr. 218, 193-200 (2003) Paragraph 1 Crystal chemical relationship between quartz (SiO2) and FePO4 Silicon dioxide is an oxide of silicon with the chemical formula of SiO2. SiO2 is a chemical compound most commonly found in Quartz and it has a space group of P3121. The lattice symmetry of SiO2 is tetrahedron, where there are 4 oxygen atoms covalently bonded to the silicon…

Abstract For this experiment the amount of zinc in vitamin water had to be determined. To do this, three methods were applied. The first was by a calibration plot method, where zinc standards were prepared and from the absorbance of those standards a calibration curve was plotted, which in turn was used to determine the amount of zinc in vitamin water. The second method was standard addition. For this method, an un-spiked and spiked solution were prepared. The un-spiked solution only contained…

The schematic diagram presented in Figure 1.1 illustrates the experimental rig used for the kinetic analysis of reactive flash volatilization (RFV) of acetol and guaiacol. The flow rates of oxygen and nitrogen gases were regulated using mass flow controllers (the type and serial number). Water, on the other hand, was delivered to an evaporator by a high-performance liquid chromatography pump (Agilent) at rates between 0.06 to 0.17 ml/min. The evaporator set at a temperature of 180C allowed to…

Nanosilver Impregnation A 400 ppm aqueous dispersion of silver nanoparticles was produced and applied to the specimens using electrochemical technique. The size range of silver nanoparticles was 30-80 nm. The pH of the suspension was 6-7; two kinds of surfactants (anionic and cationic) were used in the suspension as stabilizer; the concentration of the surfactants was three times the nano-silver particles. Empty-cell impregnation process (Rueping method) was carried out in pressure vessel under…

chemical reaction with sodium thiosulphate? Background to the Research question Chemical reaction involves the chemical change of atoms and molecules, it will occur when two or more molecules interact with each other and the molecule will change. Thus, bonds between atoms are broken down and then new molecules are formed. Hydrochloric Acid and Sodium thiosulfate are both colourless and clear liquids, and they will react together to the equation below: 〖Na〗_2 S_2 O_3 (aq)+…

Firstly, the FePO4 crystal structure comprises of both FeO4 and PO4-tetrahedral links. A tetrahedral distortion occurs when there is both a change in angle and lengths of the bonds that are present there. However, in contrast, in the case of a tetrahedral tilting, there is only a change in angle and no presence of change in bond lengths. A tetragonal distortion can be said to be a result of a tetrahedral tilt, which is due to the tilt angle delta. These are the major differences between the two…

4.3 High Performance Liquid Chromatography (HPLC) An HPLC analysis was carried out for the Fraction C2-7 for confirmation of the results obtained by TLC analysis. According to the HPLC chromatogram, there is only one peak was observed at the retention time of 4.510 minutes. Therefore, it can be concluded that there is only one compound presents in the Fraction C2-7. Basically, the first few small peaks in the chromatogram which is around 2-3 minutes are ‘noise’ from the injection that been made…

the change in the length of the bonds. The tilt angle as mentioned in paragraph 2 above, is inversely correlated with temperature. Another factor which led to tetrahedral distortion is due to the change in bond length and the change in O-PO angle which defers according to temperature. This means that when the temperature reaches roughly about 980K, the Fe—O—P bridging angles will increase and the tilt angles will decrease strongly. For the quartz-type FePO4, the bond distance and volume of the…