N12/4/CHEMI/SPM/ENG/TZ0/XX 88126104 CHEMISTRY standard level Paper 1 Friday 9 November 2012 (afternoon) 45 minutes INSTRUCTIONS TO CANDIDATES • Do not open this examination paper until instructed to do so. • Answer all the questions. • For each question‚ choose the answer you consider to be the best and indicate your choice on the answer sheet provided. • The periodic table is provided for reference on page 2 of this examination paper. • The maximum mark for this examination
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Results and Calculations Figure 1: Stress-Strain Curve – Steel 1045 Figure 2: Stress-Strain Curve – Mild Steel Figure 3: Stress-Strain Curve – Aluminium Table 1: Physical Properties of Specimens Material Initial Gauge Thickness (mm) Final Gauge Thickness (mm) Initial Gauge Width (mm) Final Gauge Width (mm) Initial Gauge Length (mm) Final Gauge Length (mm) Initial Cross-Sectional Area (mm2) Final Cross-Sectional Area (mm2) Steel 1045 6.0 5.8 12.3 11.7 50.2 57.9 73.8 67.9 Mild Steel 6
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through the system‚ to simulate lightning storms believed to be common on the early earth. Analysis of the experiment was done by chromotography. At the end of one week‚ Miller observed that as much as 10-15% of the carbon was now in the form of organic compounds. Two percent of the carbon had formed some of the amino acids which are used to make proteins. Perhaps most importantly‚ Miller’s experiment showed that organic compounds such as amino acids‚ which are essential to cellular life‚ could be made
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2.3 Magnesia-Doloma Refractories: The MgO-CaO system is remarkable for the high liquidus and solidus temperatures over the complete range 100% MgO- 100% CaO‚ as the eutectic for the CaO–MgO binary system occurs at 2370 ºC [3‚ 52]. MgO–CaO bricks are high-value refractories composed of lime (CaO) and periclase (MgO). MgO –CaO refractories has some advantageous and disadvantageous compared to MgO and CaO refractories (Table 1). Table 1 Typically‚ these refractories are composed by 50-80 wt. % of
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ELECTROPHILIC ADDITION PURPOSE The purpose of this lab is to learn how to synthesize 2-methyl-2-butene into 2-bromo-2-methylbutane using addition of hydrogen bromide. THEORY Chemical Compound Molecular Formula Molecular Weight Boiling Point Melting Point Density Amylene CH3CH=C(CH3)2 70.13 g/mol 36 oC -134 oC 0.662 g/ml Hydrobromic Acid HBr 80.91 g/mol 126 oC -11 oC 1.490 g/ml 2-Bromo-2-MethylButane C5H11Br 151.05 g/mol 107 oC 1.18 g/ml Sodium bicarbonate NaHCO3 84.007 g/mol Decomposes
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phosphorus ylide. The methyl trans-4-methoxy cinnamate produced is then analyzed using melting point and 1H NMR spectroscopy. Theory The Wittig reaction prepares alkenes from carbonyl compounds by attacking a phosphorus ylide with a nucleophilic carbon atom stabilized by a triphenylphosphonium group. An ylide is a compound that contains two oppositely charged atoms bonded together with complete octets and is generated through phosphonium salts. This experiment is a modified Wittig reaction that
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dominant‚ it is of more significant interest.In the COD test‚ the amount of oxidation that takes place depends on sample COD concentration‚ digestion time and reagent strength. It gives a measurement for the total organic carbon present in the sample.The open reflux test can be used for a large range of wastes‚ but results in hazardous wastes such as mercury and sulphuric acidbeing produced. These quantities can be reduced by the use of the closed
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EXPERIMENT NO. 2 (A) Types of cutting tools: Single-point cutting tools can be classified by their motion as linear or rotator‚ depending on whether they rotate while cutting. Linear cutting tools include tool bits (single-point cutting tools and broaches. Rotary cutting tools include drill bits‚ countersink and counter bores‚ taps and dies milling cutters and reamers. Other cutting tools‚ such as band saw blades and fly cutters‚ combine aspect of linear and rotary motion. Following are different
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1-(4nitrophenyl)ethanoate‚ this is indicated by the peak at 763.16cm-1 when compared against literature values for IR Spectroscopy shows a C-H bend in the ortho position of the phenyl ring‚ which points to the position of ethanoate being on the 4th carbon. Looking back at the yields it can be see that there has been an error in the drying process for Benzanilide resulting in a very high yield of 206%. However this is most likely to only affect the yield result‚ and not the chemical structure of
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Biochemistry‚ GRT1 Task 2 Essential Amino Acid Valine A1: 2 Characteristics of Valine • Valine is a nonpolar amino acid‚ with many carbons surrounded by hydrogen. Valine is unable to interact with water molecules‚ making it HYDROPHOBIC (MSDS‚ 2005). • Flammability- Valine is combustible at high temperatures. These products are carbon oxides and nitrogen oxides. In case of a small fire‚ dry chemical powder should be utilized. In case of a large fire‚ utilize water spray‚ fog or foam. No water
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