Percent Composition Lab Introduction
The percentage of something is very important in everyday life. For example, a farmer would want to know the percentage of nutrients in a fertilizer they are using. In spring, the farmer may want to use a fertilizer that has a high percentage of nitrogen, because it "greens” plants. In the fall, the farmer may want to use a fertilizer that has a higher percentage of potassium, because it strengthens the root systems of plants. A way to find the percentage of nutrients is by using percent composition.
Percent composition is the percent of the total mass of a compound that an element takes up (Texas A&M University, "Chemistry"). To calculate the percent composition of element of a compound, the molar mass of the compound must be found by adding up the masses of each atom in the compound (Texas A&M University, "Chemistry"). This can be done by using a periodic table. Then the mass of the element must be calculated by adding up the mass of its atoms (Texas A&M University, "Chemistry"). Then the mass of the element must be divided by the total molar mass of the compound and then be multiplied by 100 (Texas A&M University, "Chemistry"). For example, the percent composition of sodium (Na) and chlorine (Cl) in sodium chloride (NaCl) are 39.34% and 60.66%. These were found by calculating the molar mass of NaCl, which would be 22.99g/mol of sodium (Na), plus 35.45g/mol of chloride (Cl), which equals 58.44g/mol of NaCl. The total mass of sodium (Na), 22.99g/mol, was then divided by the molar mass of sodium chloride (NaCl), 58.44g/mol and then multiplied by 100, equaling a percent composition of about 39.34% of sodium (Na) in sodium chloride (NaCl). The total mass of chloride (Cl), 35.45g/mol, was then div...
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...ntahydrate is (CuSO 4 ) 5(H 2 O). The molecular formula of copper (II) sulfate pentahydrate is also (CuSO 4 ) 5(H 2 O).
Works Cited
Bailey, Dr. Kristy M. "Stoichiometry Tutorial Finding Molar Mass". Oklahoma City Community College. Web. March 17, 2014.
Chabay, Ruth; Kean, Elizabeth; Jones, Loretta; Rogers, Elizabeth; Smith, Stanley; Stovall, Iris. Fundamentals of Chemistry. University of Wisconsin-Madison, 2000. Web. March 17, 2014.
De Leon, N. "Molar Mass (Molecular Weight)". Indiana University Northwest. Web. March 17, 2014.
Department of Chemistry. "The Mole and Molar Mass". The University of Memphis, 2013. Web. March 17, 2014.
Iowa State University. "Material Safety Data Sheet Copper (II) Sulfate Pentahydrate". Iowa State University, July 9, 1999. Web. March 17, 2014.
Texas A&M University. "Chemistry". Texas A&M University. Web. March 17, 2014.
2. Cooper, M. M., Cooperative Chemistry Laboratory Manual, McGraw-Hill: New York, NY, 2009, p. 60.
The complete experimental procedure is available in the General Chemistry Laboratory Manual for CSU Bakersfield, CHEM 213, pages 20-22, 24-25. Experimental data are recorded on the attached data pages.
Physical Chemistry Laboratory Manual, Physical Chemistry Laboratory, Department of Chemistry, University of Kentucky, Spring 2006.
We thank the University of Oklahoma and the chemistry faculty for providing the space, instructions, and equipment for the development of this report and experiment.
Mass of O = Mass of crucible, cover, KClO3 and MnO2 after heating (Step # 11) - Mass of crucible, cover, KClO3 and MnO2 before heating (Step # 5)
Mass Pb(NO2)3/ MW Pb(NO3)2 to find the mass of SO4, which equaled 0.1394g, then plugged into the percentage was exactly 55.75% SO4. The begging of the experiment requested that the percentage of SO4 in their fertilizer sample be found and that is exactly what was accomplished by this experiment, and the outcome, demonstrating the ability of my group to preform the requested task presented by the
The Gravimetric Stoichiometry lab was a two-week lab in which we tested one of the fundamental laws of chemistry: the Law of Conservation of Mass. The law states that in chemical reactions, when you start with a set amount of reactant, the product should theoretically have the same mass. This can be hard sometimes because in certain reactions, gases are released and it’s hard to measure the mass of a gas. Some common gases released in chemical reactions include hydrogen, carbon dioxide, oxygen and water vapor. One of the best methods for determining mass in chemistry is gravimetric analysis (Lab Handout).
Schreuder, Jolanda A. H.; Roelen, Corné A. M.; van Zweeden, Nely F.; Jongsma, Dianne; van der Klink, Jac J. L.; Groothoff, Johan W.
David and John Free. (26 Nov 2006). MadSci Network: Chemistry. Retrieved on March 6, 2011, from http://www.madsci.org/posts/archives/2007-02/1171045656.Ch.r.html
23. S. Alwarappan, S. Boyapalle, A. Kumar, C.-Z. Li and S. Mohapatra, J. Phys. Chem. C, 2012, 116, 6556–6559
Moles HCl .0006575mol Concentration of HCl .06575 M b. Computer Data Graph: See Attached. c. 23Drops From Buret = 1mL. VI. Mathematics a. Stoichiometry Molarity = Mole(L) /
Since I am making a 0.1 Mconcentration, I will need 0.001 moles of each sugar.
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
remaining 20 percent is due to other gasses that are present in very small amounts? (Murck,