Chemistry Revision F331 Isotopes - atoms with the same atomic number‚ but different mass numbers 131I - radioactive tracer for thyroid. 99Tc for tumours. Radioisotopes - gamma emitters & short half life - long enough to detect‚ but not long enough for damage. Beta particles emitters are more useful than alpha particle emitters because they penetrate more and so are more easily detected. Also‚ less damaging. The half life is the time taken for half the isotope to decay Mass left = initial
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Abstract In the following project we are discussing about distillation. The operation of the distillation is employed for the purification of liquids from non-volatile impurities. The liquid is heated to the vapor phase and then is collected and recondensed to give back the pure liquid .The non-volatile impurities are left behind in the flask. Here our main focus will be at the fractional distillation. It is the process in which we separate the different components of a mixture on the basis of the
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bromination with hydrogen peroxide and hydrobromic acid‚ and debromination with zinc. The yields of parts A‚ B‚ and C are as follows: 68.6 %‚ 54.6 %‚ and 55.9 %. Introduction In the chemical process of bromination‚ an alkene is halogenated with bromine. Solvents that are typically used include methylene chloride and carbon tetrachloride along with iodine‚ the traditional reagent. However‚ because of the carcinogenic properties of the solvents and the corrosiveness of iodine‚ other alternatives are
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be eliminated or destroyed‚ and thus were soon advised to clean wounds and apply remedies as soon as soldiers showed signs of disease.18 Some physicians discovered the use of bromine as a sanitizing agent. William Hammond found that bromine “prevented sloughing”19 after amputations; Middleton Goldsmith placed bottles of bromine in each of the wards‚ and noted that “within 24 hours [he] saw a marked change for the better in all the patients since not one had died in the barracks from this disease except
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Relative Reactivity of Anilines Abstract: Various Anilines were tested with Br2/HBr solution‚ the products were crystallized and melting points attained to verify relative reactivity. My assignment‚ 2‚4-Dibromoanisol‚ was prepared in a yield of 52% with a melting point of 55-58 C . Reaction: Mechanism: Procedure: Anisole (0.35mL‚ 0.0378mol) was obtained and placed in a pre-weighed 25 mL round bottom flask‚ along with 2.5 mL of glacial acetic acid and a magnetic stir bar. Then the
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Elements classified as Metalloids The 7 elements classified as "Metalloids" are located in Groups 13‚ 14‚ 15‚ 16 and 17 elements of the Periodic Table. Elements classified as Metalloids have properties of both metals and non-metals. Some are semi-conductors and can carry an electrical charge making them useful in calculators and computers The Metalloids are: Boron Silicon Germanium Arsenic Antimony Tellurium Polonium Elements classified as Alkali Metals The 6 elements classified
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w w ap eP m e tr .X w om .c s er SYLLABUS Cambridge IGCSE® Cambridge International Certificate* Chemistry 0620 For examination in June and November 2014 *This syllabus is accredited for use in England‚ Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. University of Cambridge International Examinations retains the copyright on all its publications. Registered Centres are permitted to copy material from this booklet for their
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oxidation of p-xylene by oxygen in air: Diagram 3.1 The process uses cobalt-manganese-bromide catalyst. The bromide source can be NaBr‚ HBr or tetrabromoethane where bromine functions as a regenerative source of free radicals. In this process‚ acetic acid is the solvent and oxygen from compressed air is the oxidant. The combination of bromine and acetic acid is found to be highly corrosive and hence the equipment is lined with titanium. (http://en
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nitric acid to zinc granules adding concentrated sulphuric acid to solid sodium bromide adding concentrated sulphuric acid to magnesium adding iron(II) nitrate solution to acidified potassium permanganate solution adding sodium sulphite solution to bromine water adding hydrogen sulphide to acidified potassium dichromate solution adding oxygen to potassium iodide in alkaline medium to give iodine and hydroxide adding carbon to concentrated sulphuric acid adding copper to silver nitrate
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Experiment 5- Competing Nucleophiles Table of results: Area (mm²) Percent composition 1-bromobutane 511 85.02% 1-chlorobutane 90 14.98% 2-bromobutane 432.25 78.63% 2-chlorobutane 117.5 21.37% 2-bromo-2-methylpropane 280 37.58% 2-chloro-2-methylpropane 465 62.42% Discussion: 1. In 1-butanol Base on the data table‚ 1-bromobutane dominated the composition of 85.02%‚ which indicates the conclusion that the mechanism for 1-butanol is SN2‚ and bromide is a better nucleophile
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