1. Hydrogen Name: Hydrogen Atomic number: 1 Atomic Weight: 1.00794 grams/mole Standard state: gas at 198 K Hydrogen is the lightest Hydrogen is the lightest element. It is by far the most abundant element in the universe and makes up above 90% of Universe by weight. Hydrogen as water (H2O) is absolutely essential to life and it is present in all organic compounds. Hydrogen is lightest gas. Hydrogen gas was used in lighter-than-air balloons for transport but is far too dangerous because
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Preparation u Alcohols when heated in presence of H2SO4‚ H3PO4‚ P2O5‚ Al2O3 or BF3 undergo loss of water molecule with the formation of alkene. Conc. H2SO4 180oC H3PO4/P2O5 200oC Al2O3/BF3 350oC CH3-CH=CH2 + H2O CH3-CH2-CH2-OH CH3-CH=CH2 + H2O CH3-CH=CH2 + H2O u u Mechanism: In the first step OH group of the alcohol is protonated in a fast reversible reaction. Unlike OH group‚ protonated OH group is a good leaving group. Step 1: CH3 CH3-C-CH3 + H+ HO CH3 CH3-C-CH3 H2O+
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THE PERIODIC TABLE HISTORICAL BACKGROUND The idea that all things are elements or combinations of elements can be found in the writings of the ancient Greeks and other early peoples. Although this idea may seem simple‚ it is very difficult to decide if a substance is indeed an element or a compound. There were twelve chemical elements discovered in ancient times‚ but it was not known that they were elements. Another 76 elements were discovered between 1557 and 1925. Many mistakes were made in
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CHEMISTRY SAMPLE PAPER - I CLASS - XII Time : Three Hours Max. Marks : 70 General Instructions 1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each 6. Use log tables if necessary‚ use of calculators is
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Abstract Tamoxifen‚ most commonly sold under the brand name Nolvadex‚ is the most widely used drug in the treatment of breast cancer during both early and late stages. It belongs to a class of drugs known as SERMs (Selective Estrogen Receptor Modulators). SERMs work by blocking the estrogen receptors in breast cells to prevent any binding with estrogen. It is consumed orally as a tablet or as a liquid (Anon.‚ 2017). The following paper discusses the discovery of Tamoxifen‚ its laboratory synthesis
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Swimming Rejuvenating‚ the body mind and spirit…. Fitness development The fitness development of swimming can be classified into1 group and 2 sub-sections: Performing swimming regularly can help one in building cardio which is important for both weight loss and good cardiovascular health. When the workout is increased gradually by swimming strokes in the water‚ the heart rate and muscle activity is improved. This increases blood flow to your muscles‚ which results in more nutrients being delivered
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Chemical Thermodynamics Chapter 19 Lecture Worksheet Homework: 19.29‚ 19.31‚ 19.37‚ 19.39‚ 19.41‚ 19.43‚ 19.47‚ 19.51‚ 19.53a‚ 19.55‚ 19.61‚ 19.73‚ 19.75‚ 19.77 Recall from Chapter 5 - 1st Law of Thermodynamics o Energy is neither ____________________________________________. o Energy of the universe is constant. o Enthalpy Change ▪ Heat energy transferred at _____________________________________ ▪ Negative
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A. MATTER * Nature of matter. * Describe the states of matter and explain their conversion in terms of the kinetic particle theory. * Describe and explain diffusion. * Describe dependence of rate of diffusion on molecular mass‚ qualitatively. * Experimental techniques Measurement. * Name appropriate apparatus for the measurement of time‚ temperature‚ mass and volume‚ including burettes‚ pipettes and measuring cylinders. Criteria of purity. * Identify substances
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Chapman et.al (2009) studied the local impact of hoisted point sources on late spring aerosol driving and cloud-aerosol cooperations‚ in northeastern North America‚ was studied by utilizing the WRF-Chem community model. The immediate impacts of mist concentrates on approaching sun powered radiation were recreated utilizing existing modules to relate aerosol sizes and chemical composition to airborne optical properties. Direct impacts were reenacted by including a prognostic treatment of cloud bead
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Case 11: Great Lakes: Great Decisions Report Jessita Herriott Mr. Bill Loelius Bus. 499 (Senior Seminar) October 20‚ 2010 Great Lakes’ Immediate‚ impending‚ and Invisible Competitors and How G.L. Measure’s Up Great Lake’s bad public relations image is its only immediate‚ impending and invisible competitor. The industry environment that Great Lakes is situated in is one that is characterized by global market shifts and pressures. At the moment‚ Great Lakes does not have any competition from
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