Purpose The goal of this lab is to find out which metals were used in the minting of pennies before and after 1982 by calculating their densities. Hypothesis If the penny was made after 1982 then its density will be higher than those made before 1982. Materials • 1 Graduated cylinder • 30 mL of water • 10 pennies minted before 1982 • 10 pennies minted after 1982 • 1 electric scale Procedure The mass of ten pennies minted before 1982 was calculated five times using the scale and then averaged
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word as used in your textbook? A. B. C. D. E. air tap water sea water water toothpaste 2. Select the best statement. A. B. C. D. E. Physical changes may be reversed by changing the temperature. Physical changes alter the composition of the substances involved. Physical properties are not valid characteristics for identifying a substance. Physical properties are mostly extensive in nature. Physical changes are usually accompanied by chemical changes. 3. Select the best
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RESULTS AND DISCUSSION: Ultraviolet spectroscopy of Verapamil hydrochloride at λmax of 278 nm in pH 1.2 buffer was found to be linear in range of 20 – 80 µg/ ml. The method was validated and found to be precise‚ specific and accurate. The tablets of Verapamil hydrochloride were prepared by press coating technique showing sustained release for 24 h for once daily dosing with a lag phase of 4 - 6 h. The optimum ratios and type of polymers and other excipients were chosen to produce gastroretentive
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fast green‚ and the chlorophylls‚ also in the case of fast green create a concentration curve to determine an unknown substance. Each test will use the spectrophotometer. Spectroscopy is the study of light. A spectrophotometer is a machine used to determine the absorbance of light at any given wavelength. It does this by using a source of white light through a prism‚ which gives multiple wavelengths that can be individually focused (Ayyagari and Nigam‚ 2007). Substances are put into cuvettes that
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table above‚ the mass of penny‚ copper‚ and zinc was needed in order to determine the percent composition of copper and zinc. The mass of penny was taken on the scale in the beginning of the procedure before anything was done to the penny‚ and it was 2.51 grams. After the reaction with the hydrochloric acid and drying the copper‚ the mass is 0.35 grams. To get the mass of zinc‚ the mass of the penny was subtracted by the mass of copper. The mass of zinc is 2.16 grams. The penny is 14% copper and 86%
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Copper and Zinc Composition Percentages in Pennies Introduction. The United States Mint sends copper and zinc to a fabricator‚ which creates coin-sized discs called planchets. The planchets undergo the coining press at the Mint where they are stamped as genuine United States legal tender coins. The purpose of this experiment is to determine the accuracy of the copper and zinc composition percentages in a random sampling of pennies. The penny was dissolved to make aqueous copper ions and four copper
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Atomic Spectroscopy using a Constant Deviation Spectrometer with Fabry-Perot Etalon Abstract A constant deviation spectrometer with Fabry-Perot etalon has been used to investigate the various atomic emission characteristics from a Zn-Cd-Hg lamp‚ a low pressure Hg lamp and a Ne lamp. The Fabry-Perot etalon of Free Spectral Range 0.010 cm-1 was used to resolve the fringes of the Hg 546.0731nm spectral line‚ and the 594.4834nm‚ 614.3063nm‚ 640.2246nm and 650.6528nm spectral lines of the Ne lamp
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Penny-Ante Equilibrium Introduction What is equilibrium? What happens to the amount of reactants and products when equilibrium is reached? What if more reactants or products are added to a system already at equilibrium? In this activity‚ pennies will be used as reactants and products in a reversible reaction to answer these questions and learn more about the fundamental nature of equilibrium. Concepts • Reversible reactions • Equilibrium • Equilibrium constant • LeChatelier’s principle Materials
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This lab report will be detailing the steps taken and the results discovered when using spectrophotometry to determine the percentage of copper in a copper-clad penny and the thicknes of the copper layer on the copper-clad penny. After 1982‚ copper coating has been used in the creation of the penny because the cost of pure copper has increase to the point that the amount needed t omake a penny cost far more than the actual value of the penny. This lab allowed us to see just how much copper coating
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Mass Spectroscopy Mass spectroscopy is a method used in science and industry in order to obtain the masses and relative concentrations of atoms and molecules and to detect isotopes in a sample based on their masses. In order to do this the method requires an instrument called the ‘mass spectrometer’‚ of which‚ is able extract accurate information of the relative masses of isotopes and their relative abundance. This makes the mass spectrometer very useful for applications such as carbon dating
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