JPJC Prelim 2025 Paper 4 Prep List_H2 Chem

© Jurong Pioneer Junior College [Turn Over JURONG PIONEER JUNIOR COLLEGE 2025 JC2 H2 CHEMISTRY (9729) Preliminary Examination Paper 4 (Chemical and Apparatus List) Label Identity Preparation per candidate FA 1 sodium hydrogencarbonate Provide 6.0–6.1g of NaHCO3 in a suitable container 6.0 g FA 2 1.0 mol dm–3 sulfuric acid, H2SO4. Cautiously pour 55 cm3 of concentrated (98%) sulfuric acid into 500 cm3 of DI water with continuous stirring. Make the solution up to 1 dm3 with DI water. Care: concentrated H2SO4 is very corrosive. 100 cm3 FA 3 0.0100 mol dm–3 sodium thiosulfate, Na2S2O3. Dissolve 2.482 g hydrated Na2S2O3.5H2O (or 1.582 g anhydrous Na2S2O3) in DI water, then made up to 1 dm3 with DI water. 200 cm3 FA 4 0.0200 mol dm−3 potassium manganate(VII), KMnO4. Dissolve 3.16 g of KMnO4 in each dm3 of solution. 60 cm3 FA 5 0.200 mol dm−3 ethanedioic acid, H2C2O4. Dissolve 18.0 g anhydrous H2C2O4 (or 25.2 g hydrated H2C2O4.2H2O) in DI water, then made up to 1 dm3 with DI water. 100 cm3 FA 6 0.100 mol dm–3 potassium iodide, KI. Dissolve 16.6 g of KI in DI water, then made up to 1 dm3 with DI water. 100 cm3 FA 7 zinc carbonate and potassium iodide Mix ZnCO3 and KI thoroughly in the mass ratio of 2 : 1. Provide in a stoppered container. Any form of basic zinc carbonate is suitable. 2.0 g FA 9 0.5 mol dm-3 ethanoic acid 10 cm3 FA 10 10% (v/v) aqueous solution of ethanol (in stoppered glass vial) 10 cm3 Hot water Central supply Temp of water set at 90 oC. 200 cm3

2 © Jurong Pioneer Junior College 9729/04/J2 PRELIMINARY EXAM/2025 [Turn Over On Student’s Bench Reagent Rack: Label Identity Preparation Dilute nitric acid 2.0 mol dm–3 HNO3 Dilute 128 cm3 of concentrated (70%) nitric acid [C][O] to 1 dm3 aqueous ammonia 2.0 mol dm–3 NH3 Dilute 112 cm3 of concentrated (35%) ammonia to 1 dm3 using DI water. aqueous sodium hydroxide 2.0 mol dm–3 NaOH Dissolve 80.0 g of NaOH in each dm3 of soln. Care: the process of soln is exothermic and any concentrated soln is very corrosive. aqueous silver nitrate 0.05 mol dm–3 AgNO3 Dissolve 8.5 g of AgNO3 in each dm3 of soln. limewater saturated aqueous calcium hydroxide, Ca(OH)2 Prepare fresh limewater by leaving distilled water to stand over solid calcium hydroxide for several days, shaking occasionally. Decant or filter the soln. aqueous potassium manganate(VII) 0.02 mol dm–3 KMnO4 Dissolve 3.16 g of KMnO4 in each dm3 of soln. Iodine solution Aqueous iodine, I2. Dissolve 10 g of I2 and 20 g of KI in 100 cm3 of DI water. Magnesium turnings Place magnesium turnings in a capped container. (students will use 1 spatula. Last for 3 shifts) Starch Indicator freshly prepared aqueous starch indicator (approx 2% solution w/v) Mix 2 g of soluble starch with a little cold water until a smooth paste is obtained. Add 100 cm3 boiling water and stir. Boil until a clear solution is obtained (about 5 minutes). Red litmus pa