Absorption spectroscopy

After Draper’s death, his widow agreed to fund astronomer Edward Pickering’s research in photographic spectroscopy on the condition that it be named after her husband. (James) In 1885, Pickering began his research at Harvard University with the goal of creating a full-sky star catalogue, categorizing stars based on their spectra. This was the first large-scale…

The purpose of this spectroscopy experiment was to determine if the spectra matched the electronic transitions that occur in the hydrogen atom among several other atoms. We used the Bohr model of atomic structure to determine the orbit numbers that correspond with the spectrum emitted by the hydrogen atom. The Bohr model states that electrons will never be found in between states, but rather completely in one state or the other. We used this model to determine the initial n value at which the…

B Sridhar et al (2012) studied Purification and Characterization of Biosurfactants. The emulsifications of biosurfactants were checked in various oils such as olive, coconut, sunflower and rice bran oils, the emulsification activity of biosurfactants. Pseudomonas aeruginosa had higher emulsification activity than Saccharomyces cerevisiae. While checking the sugar and lipid content in biosurfactants by phenol sulphuric acid method and vanillin reagent method, found high in Pseudomonas aeruginosa…

spectrophotometric method is discussed. The spectrophotometry is a method that involve in infrared spectrum and a quantitative measurement of the reflection of a material and it represent as a function of wavelength. Thus the infrared spectroscopy (IR spectroscopy) is the spectroscopy that deals with the infrared region of the electromagnetic spectrum that is, light with a longer wavelength and lower frequency than visible light. Infra-red spectrum is usually divided into 3 spectral regions…

The objective of this experiment is to prepare isopentyl acetate by direct esterification of acetic acid and isopentyl alcohol. Esterification is carried out by utilizing organic chemistry techniques, such as heating under reflux, extraction, and simple distillation. The acid and alcohol would be combined and heated under reflux; which heats/speeds up the reaction without having the reactants/products evaporate or explode. During reflux, the heating and condensing of the vapor prevents any loss…

concentration of phosphate by using spectroscopy. Dilutions of a phosphate working solution with a known concentration were made and their absorption lengths were found using the spectrometer in order to find the concentration of the unknown phosphate sample. INTRODUCTION The goal of the experiment was to find the concentration of an unknown water sample using several standard phosphate solutions’ absorbencies and Beer’s Law. Knowing the relationship between the absorption of light and…

Introduction: The purpose for this experiment is to carry out the dehydration of 2-methylcyclohexanol, which undergoes an E1 mechanism by following Saytzev’s rule to form different product such as 1-methylcyclohexanol, 3-methylcyclohexanol and methylenecyclohexane. The reaction can be dehydrated using sulfuric acid and H3PO4. The dehydration mechanism occurs in several steps like – 1. Converting the OH group into a better leaving group that is deprotonating with H3PO4. 2. Removing a…

In the first step of the experiment, m-toluic acid reacted with thionyl chloride to form the acid chloride derivative of m-toluic acid. In this reaction, the carboxylic acid is first converted into an acyl chlorosulfite intermediate, replacing the –OH of the acid with a better leaving group. The acyl chlorosulfite then reacts with a nucleophilic chloride ion, at which point the chlorosulfite leaves in the form of sulfur dioxide and chloride ion. The remaining acid chloride then reacts with…

Haemoglobin (Hb) and Myoglobin (Mb) have similar absorption spectra. Delineating each of their contributions to TOI values is not possible. As desaturation of Mb is minimal at 3 minutes of vascular occlusion, one can assume that the TOI values will represent changes in oxygenation of Hb. \cite{Ferrari:2004uc}\\…

Transmission electron microscopy, or TEM, is a variation of low field, high-powered electron microscopy. Created by Ernest Ruska and Max Knoll of the Berlin Technische Hochschule in 1931, the invention of this novel microscope allowed for the surpassing of the visible light resolution barrier. Since its inception, the TEM has become a resolution standard in the field of imagery, and further advances have led to the progression of high quality atomic viewing. The development of the electron…