Sample essay topic, essay writing: Molecular Structure - 638 words
Molecular Structure LabObjective:For this experiment we took two different molecule and virtually dissected them finding everything about them including: bond length, bond angles, the charge on each atom, the non bonded distances between atoms and the energy difference between the highest and lowest molecular orbital. Procedure:The procedure is to use HyperChem Lite to get the information needed from each molecule. But explained in full on page 16 and 17 in the lab manual. Data:The following data was found about CH4 (methane).o The bond length from Carbon to all four Hydrogen atom was the same measurement that came to be about 1.113Ao Not only are the lengths between all the Hydrogen atoms to the Carbon atoms the same so are the angles between the hydrogen atoms, all coming out to be about 109.47^0.o The non-bonded distances between all the parts of the molecule are 1.818A. o The charge on the Carbon atom is -.143o All of the hydrogen atoms have the same charge being.036The following data was collected by HyperChem Lite for C2H5OH (ethanol).o All the distances between bonded Carbon and Hydrogen atoms were 1.115A. o The distance of the bonded oxygen (3) to hydrogen (9) was.942A. o The distance between bonded Carbon (1) to Oxygen (3) was 1.40A. o Bond angle 5,1,4 was 109.8^0o Bond angle 3,1,2 was 108.9^0o Bond angle 6,2,8 was 107.9^0o The smallest non-bonded distance was between atoms 9 (hydrogen) and 6 (hydrogen) it was 4.067A. o The largest distance between two atoms was from 6 to 8 1.802A. o The charge on the Carbon atoms were: Carbon 1=.466, and Carbon 2=-.076o Hydrogen charges were as follows: Hydrogen's 4,5=-.004, 6=.021, 7,8=.020, and the charge of hydrogen 9=.447o And lastly the charge on the oxygen atom was -.891Calculations:Formulas used in the lab..E = hv = hc/1 ev = 1.6022E-19 JoulesE is the energy difference between the highest occupied and lowest unoccupied molecular orbital (HOMO and LUMO).h = Plank's constant = 6.63E-34 Jsc = speed of light = 3.00E8 m/sformal charge = number of valence electrons - (# of unshared electrons + # of bonds)Volume of an ellipsoid is V = /6 (a + 1A)(b+1A)(c+1A) = xA3A, b,and c are the skeletal lengths of the molecule. CH4E = (-15.51ev)-(-24.49ev) = 8.98ev = 1.44E-18 J = hc/E = (6.63E-34 Js)(3.00E8 m/s)/(1.44E-18 J) = 1.38E-7 m = 138nmThe wavelength of CH4 is 138nm and this resides in the ultra-violet spectrum and is not visible to the naked eye. Formal charge of Carbon = 4-(0+4) = 0Formal Charge of Hydrogen's = 1-(0+1) = 0These charges (formal) found above are not equal but similar to the charges found by HyperChem Lite using Huckel's theory.
Huckel's numbers are much closer to the actual charge of each atom. Volume of methane = 29A3Cooking gas is one of the main uses of methane. C2H5OHE = (-13.93ev) - (-33.94ev) = 20.03ev = 3.209E-18 J = hc/E = (6.63E-34 Js)(3.00E8 m/s) / (3.209E-18 J) = 6.198E-8 m = 62nmThe wavelength of C2H5OH is 62 nm and resides in the ultra-violet spectrum and is not visible to the naked eye. Formal charge of Carbon atoms = 4 - ( 0+4) = 0Formal charge of Oxygen atom = 6 - (4+2) = 0Formal charge of all 6 Hydrogen atoms = 1 - (0+1) = 0These charges found above are not equal to the actual Huckel charges but similar to. Volume of ethanol = /6(4.067A+1A)(2.241A+1A)(3.131A+1A) = 35.52A3Where a is atoms 9 to 6, b is atoms 5 to 9, and c is atoms 4 to 8 Ethanol is the active ingredient in all alcoholic beverages. Conclusions:In this experiment we dissected methane and ethanol and found everything from there bond lenths to there uses, and along the way found there charges, angles, and volumes. This was a good lab because I'm sure being a Pharmacy major that I am I will be using this program in Organic chemistry next year. HyperChem Lite was a quick was to find out valuable information about molecules.
Research paper and essay writing, free essay topics, sample works Molecular Structure
Molecular Structure