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1 MJC Prelim 2017 H2 Chemistry1Magnesium carbonate is a white solid that is readily found in nature. In this experiment, you will determine the percentage purity of a sample impure magnesium carbonate. FA 1is a sample of impure magnesium carbonate. You may assume that only the magnesium carbonate present in the sample will react with the acid. You will first dissolve FA 1 in excess hydrochloric acid. MgCO3(s) + 2HCl(aq) →MgCl2(aq) + H2O(l) + CO2(g) The resulting solution will then be titrated using sodium hydroxide. You may assume that no compounds present in FA 1will react with the sodium hydroxide. NaOH(aq) + HCl(aq) →NaCl(aq) + H2O(l) FA 1 is impure magnesium carbonate. FA 2 is 2.0 mol dm-3hydrochloric acid, HCl. FA 4 is 0.20 mol dm-3sodium hydroxide, NaOH. methyl orange indicator (a) Procedure Preparation of standard solution1. Fill a burette with FA 2. 2. Run between 47.50 and 48.50 cm3of FA 2 into a 250 cm3beaker. 3. Record your burette readings and the volume of FA 2in the space below. 4. Weigh accurately about 2.0 g of FA 1in a weighing bottle. 5. Transfer the FA 1from the weighing bottle as fully as you can into the beaker containing FA 2. 6. Reweigh the weighing bottle and record all masses in the space below. 2017 MJC H2 Chemistry Prelim Paper 4
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