to determine the melting and freezing points of pure Na2S2O35H2O. • Interpret the changes in energy and entropy involved in these phase changes. • Verify the observed melting point against the accepted melting point found in reference data from two different sources. • Use the graph to qualitatively determine whether there are impurities in a sample of Na2S2O35H2O. OBJECTIVES Observe the temperature and phase changes of a pure substance. Measure the time needed for the melting and freezing of a
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ability were also labeled as the enemy. In four years‚ the Khmer Rouge caused the deaths of nearly a quarter of Cambodia’s population and scarred its survivors. For four years‚ the Khmer Rouge‚ founders of the Communist Party of Kampuchea‚ led by Pol Pot (a.k.a. Saloth Sar)‚ gained control over Cambodia in a coup d’etat and declared the beginning of Year Zero‚ their attempt to reset the country and create an agrarian society. Official government forces led by Lon Nol succumbed to the Khmer Rouge at
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out with friends‚ the out of no where being taken away to a labor or death camp to be murdered or worked to death. This is what the Khmer Rouge did to Cambodians. Pol Pot and the Khmer Rouge caused the deaths of many Cambodians through labor and death camps during the 1970’s. Origin The Khmer Rouge was a Communist party led by Pol Pot in Cambodia. They took control of the country from 1975 to 1979‚ and outlawed money‚ religion‚ and family (Molloy). Citizens of Cambodia were not allowed to own money
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Stability evaluation of organic Lip Balm Alessandra Ribeiro Fernandes‚ Michelli Ferrera Dario‚ Claudinéia Aparecida Sales de Oliveira Pinto‚ Telma Mary Kaneko‚ André Rolim Baby‚ Maria Valéria Robles Velasco* Department of Pharmacy‚ Faculty of Pharmaceutical Sciences‚ University of São Paulo Rising global demand for natural products whose production is harmless to the environment has stimulated the development of natural cosmetics and‚ within this category‚ organics (95% organic raw materials)
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During the last three decades‚ Cambodia has suffered through war‚ political disorder and genocide. On April 17th 1975 after winning the civil war‚ the Khmer Rouge gained the control of the Phnom Penh. This communist guerrilla group led by Pol Pot would cause unimaginable devastation and misery throughout Cambodia for the next three years‚ eight months and twenty days. The Khmer Rouge forced the people of Cambodia to the countryside and to labor camps. Families were separated‚ children
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everyday whether it will be your last. All your body feels is pain; all your heart feels is emptiness. One might think this is how life was for Jews during the Jewish Holocaust. In reality‚ this is how life was for many Cambodians during the reign of Pol Pot between 1975 and 1979. This event‚ known to many as the Cambodian genocide‚ left a profound mark on the world around us. In the late 70’s‚ nearly 2 million Cambodians died of overwork‚ starvation‚ torture‚ and execution in what became known as the
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Abstract Finding the melting point of an organic substance is a practical and efficient way for scientists to identify an unknown substance or determine a known substance’s level of purity. When organic substances are mixed together in varying degrees they take on a melting characteristic that is lower and broader than in its pure form. This property was manipulated in the lab to observe the various melting points of Naphthalene and Biphenyl when the percentage of composition was altered. A
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Determination of Melting and Boiling Point of different Organic Compounds Bakare‚ Abimbola Kristine‚ C. Professor Miranda Marilyn‚ school of chemical engineering and biotechnology‚ Mapua Institute of Technology‚ CHM145L-B11 ABSTRACT A melting point of a solid is the temperature at which the first crystal just starts to melt until the temperature at which the last crystal just disappears. Thus‚ the melting point (m.p.) is actually a melting range. The melting point of a substance depends
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CHE 173 Sec # January 25‚ 2005 Experiment 36: Determination of the Structure of a Natural Product in Anise Oil Purpose: The purpose of this experiment is to isolate the major component of anise oil and determine its identity and structure using melting point determination and IR spectroscopy. Introduction: The major component of anise oil has the chemical formula C10H12O. This compound is said to be hydrogen deficient‚ meaning that it contains less hydrogen atoms than would be needed for each
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filtration and melting point. Chm237 Abstract: Acetaminaphen was crushed then extracted for the active ingredient by mixing it with methanol. Then separated from the binders by centrifugation and a filtration technique using a Pasteur pipet packed with alumina. The remaining solvent was then evaporated to yield the solid analgesic(.2295g‚ 45.9% yield) which was collected by filtration and tested for the purity of the drug by the melting point determination. The melting point was
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