In this experiment, we computationally predicted the dipole moments of 5 different analyte molecules using the program Spartan. We constructed the molecules online as the program then calculated their dipole moments (polarity). We then experimentally determined the 5 analyte molecules retention factors using the TLC method in the lab. Polarity in organic chemistry refers to a separation of electric charge leading to a molecule having an electric dipole moment1. To determine whether a molecule is polar or nonpolar depends on a molecules structure. This is done by comparing the electronegativity’s of each element in the molecule that are bonded to each other. If a molecules dipole moment eliminates each other due to its symmetrical shape, it is considered to be …show more content…
Vice versa, if a molecules dipole moment doesn’t cancel out, due to its asymmetrical structure, it is then considered to be a polar molecule. It is predicted that the higher the Rf value, the lower the dipole moment of a molecule and vice versa2. This is experimentally proven correct, except for the one compound, 2-Decanol. The polarity of 2-Decanol was known to be 1.52 D based off of the Spartan program. Compared to the other analyte compounds it was shown that 2-Decanol was the fourth highest in its dipole moment value, therefore it was expected to have the fourth lowest retention factor value. However, in our calculations, 2-Decanol has the lowest retention factor value. Ignoring the ambiguity of 2-Decanol, it was proven that the compound 1-Decene had the lowest polarity, and the highest Rf value. Butyl Butyrate had the second lowest polarity, and the second highest Rf value. 2-Decanone has the second highest polarity, and the second lowest Rf value. And lastly, Decanoic Acid has the highest polarity, and the lowest Rf value, again dismissing
There is a technique called polarimetry that uses polarized light and asymmetric carbons like those found in glucose. The amount of polaritization can be used to determine the amount of active molecules present in solution.3 The equation used is measured rotation of angle = (a)lc, (a) is optical activity, c is the concentration, and l is the pathlenght. The concept seems similar to Beers
The goal of this lab is to exemplify a standard method for making alkyne groups in two main steps: adding bromine to alkene groups, and followed by heating the product with a strong base to eliminate H and Br from C. Then, in order to purify the product obtained, recrystallization method is used with ethanol and water. Lastly, the melting point and IR spectrum are used to determine the purity of diphenylacetylene.
Experimental and Computation Vibration-Rotation Spectroscopy for Carbon Monoxide Through the Use of High-Resolution Infrared (IR) Spectra
Abstract: Various Anilines were tested with Br2/HBr solution, the products were crystallized and melting points attained to verify relative reactivity. My assignment, 2,4-Dibromoanisol, was prepared in a yield of 52% with a melting point of 55-58 C .
People have often pondered the reasons for the greatness of Edith Wharton's novel, Ethan Frome. What is it that causes this story to be considered an all-time American classic? One journalist quotes a humanities professor at MIT who states that, "We turn to Wharton because the truths she tells are a bracing tonic in a culture steeped in saccharine sentimentality." The journalist goes on to describe the typical, "popular" story and how they often have endings where "romantic ideals are magically fulfilled..." There is much more to Ethan Frome than simply an unhappy ending to contrast with the many other stories that have sugar-coated and sanguine endings. At first glance, the ending of Ethan Frome may appear to be only depressing. In truth, Wharton offers the reader a complex ending through the careful incorporation of poetic justice and irony.
1 Liu Xiaotong Liu Dr. Bobbitt COM 325 19 February, 2016 The Love Beyond Gravity The film Upside Down, which released in 2012, is a Canadian-French romantic fantasy film. Its director is Juan Solanas.
Thickett, Geoffrey. Chemistry 2: HSC course. N/A ed. Vol. 1. Milton: John Wiley & Sons Australia, 2006. 94-108. 1 vols. Print.
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23. S. Alwarappan, S. Boyapalle, A. Kumar, C.-Z. Li and S. Mohapatra, J. Phys. Chem. C, 2012, 116, 6556–6559
Hydrolysis of aspartame under acidic or basic conditions results in aspartic acid, phenylalanine and methanol. Several solutions can be prepared in order to study the amino acids of aspartame. With TLC analysis, we were able to observe the polarity of each of the solutions prepared. Out of all the solutions, aspartic acid has the lowest Rf value because it is a charged amino acid, therefore it is polar. The solution with the highest Rf is phenylalanine because it is a hydrophobic amino acid.
1-Butanol with intermediate polarity was soluble in both highly polar water and non polar hexane as 1-butanol can be either polar or non polar compound. 1-Butanol was polar based on the general rule of thumb stated that each polar group will allow up to 4 carbons to be soluble in water. Also, 1-butanol can be non polar due to their carbon chains, which are attracted to the non polarity of the hexane.
Pauly, S. (2011, February). News from ABC: changes and challenges. Analytical & Bioanalytical Chemistry. pp. 1003-1004. doi:10.1007/s00216-010-4459-0.
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
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.
One significant advantage of capillary electrophoresis (CE) is the separation of a broad range of analytes at the same moment. Affinity Capillary Electrophoresis (ACE) is a technique used in order to separate substances which participate either in specific or in non-specific affinity interactions during the electrophoresis process, by using a capillary electrophoresis format. The molecules can be free in solution or they can be immobilized to a solid support (Heegaard, Nilsson and Guzman, 1998).