NSS Chemistry Part 15 Analytical Chemistry (Structural Questions) HKCEE and HKAL Past Paper Questions 1. HKCEE 1994 Q8b A student carried out some tests on an ionic compound X which was a white solid. The results obtained were summarized in the following flow diagram: (i) Based on the above information‚ deduce the cation and anion present in X. (ii) Describe how the flame test on X can be carried out in the laboratory. (6 marks) 1 2. HKCEE 1995 Q2 In each of the following
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percent yield of cyclohexene. Lastly‚ a bromine test was carried out to quantitatively test the presence of cyclohexene product in the prepared sample. A total of 2-3 drops of 3% bromine in dichloromethane was added to a new test tube as well one drop of the prepared cyclohexene. Upon observing a color change from brown to clear‚ one can confirm the presence of cyclohexene in the obtained
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Edexel IGCSE Chemistry Revision Notes IGCSE Chemistry Triple Award Revision Guide Topic Introduction to chemistry Atomic Structure Structure and Bonding – Ionic Bonding Structure and Bonding – Covalent and Metallic Bonding Organic Chemistry - Alkanes Organic Chemistry – Alkenes / Addition Polymerisation Organic Chemistry – Alcohols / Condensation Polymerisation Calculations Periodic Table Reactivity Series and Metal Extraction Electrolysis Energetics Acids‚ Bases‚ Salts and Neutralisation Preparing
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Naming Chemical Compounds General Information: Scientists all around the globe use a standard method for naming chemical compounds. The standards were set up by an international committee sponsored by the International Union of Pure and Applied Chemistry (IUPAC). Having this standard makes life easier for people who use these compounds everyday. It would be tough to set up any experiment if scientists everywhere used different names for the same compound. It would also make the lab a
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of byproduct gases observed in the university pool. Within my research I learned that other schools were discovering the harmful affects of chlorine in their pools as well. With other communities and colleges creating the positive change toward bromide‚ we can look at their transformation process and learn from their
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compound Functional group(s) Alkanes CH3CH3 ethane C – C and C–H Alkenes CH2 = CH2 ethene C=C Chemical tests/Observations Add liquid bromine in ultraviolet light (or sunlight): White fumes of HBr liberated; decolourisation of bromine occurs slowly (a) Add Br2 in CCl4 at room temperature: Decolourisation of bromine occurs immediately CH2 = CH2 + Br2 → CH2BrCH2Br (b) Add acidified KMnO4 at room temperature: Decolourisation of KMnO4 occurs immediately CH2 = CH2 + [O]
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through a cycle of 6 carbon atoms with 3 double bounds was proposed by Kekule in 1865: In some special conditions‚ benzene can be hydrogenated‚ the result being a cyclic hexane: | +3H2 | | Under the influence of light‚ chlorine or bromine addition at the benzene’s molecule giving hexachlorocyclohexane: C6H6 + 3Cl2 C6H6Cl6. With ozone‚ the benzene gives a trizonide‚ which by decomposing (with water)‚ passes in glycoxal. These addition reactions prove the following: benzene has a cycle
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iodine will be added to a test tube using a dropper in lieu of a graduated cylinder. Appearance of solution will be recorded. Then‚ 1mL of hexane will be added to the test tube mix. Observations of both layers will be recorded. Process repeated for bromine. For the third solubility test‚ 1mL of hexane will be added to a clean test tube. Then‚ 0.5mL of Clorox and 0.5M HCl (to make chlorine) are added. The color of each layer is noted. Part III: Electronegativity Testing This set of reactions
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accordance with Edexcel Limited copyright policy. ©2011 Edexcel Limited. Printer’s Log. No. Turn over N36637A W850/U7081/57570 5/5/5/ *N36637A0120* Leave blank Answer ALL the questions. 1. Complete the table. Name of compound calcium bromide NH4NO3 sodium sulphite copper(I) oxide PbO2 iron(III) sulphate Q1 (Total 6 marks) Formula of compound 2 *N36637A0220* Leave blank 2. Complete the following statements by inserting the missing colours. (a) When water is added to anhydrous
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2. (i) iodide has been converted to iodine (1) (with correct use and spelling of iodide and iodine) The 1st experiment shows that bromine is more reactive than iodine (1) The 2nd experiment shows that chlorine is more reactive than bromine (1) Accept 1 mark for 2nd and 3rd marking points if the correct reactivity order of chlorine > bromine > iodine has been stated. 3 (ii) Br2 + 2I– 2Br– + I2 (1) 1 [4]
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