Shake well and use for the tests below: (a) To the 2cm 3 of solution in a test-tube, add one spatula end full of sodium hydrogen carbonate (b) To 2cm 3 of solution, add three drops of acidified potassium manganate (VII) solution (c) Place about 5cm 3 of ethanol in a test tube and add drops of concentrated sulphuric acid then add a spatula end full of solid X . warm the mixture carefully. Shake well and pour the mixture into 20cm 3 of water in a beaker CONFIDENTIAL Requirements:- 1. Solution X 1 , acidified potassium manganate (VII) solution. It is prepared by dissolving 3.16g of KMnO 4 in 400cm 3 of 2M H 2 SO 4 . add distilled water to make it up to 1litre solution 2. Solution X 2 , 0.1M Iron (II) Sulphate –It is prepared by dissolving 20.8G of Iron (II) Sulphate in1litre of distilled water, add a few drops of concentrated sulphuric (VI) acid, to avoid oxidation. 3. Solution X 3 contains 3.45g of sodium nitrite in 1 litre of solution 4. Solid M – Potassium nitrate 5. Solid Y - (Oxalic acid) 1. You have been provided with: (i) Solution X 1 , acidified Potassium manganate (VII) solution (ii) Solution X 2 , 0.1M FeSO 4 (iii) Solution X 3 , Sodium Nitrite You are required to: (a) Standardize solution X 1 , using X 2 (b) Use experimental results to write ionic equation for the reaction between manganate (VII) ions and nitrate ions Procedure I:- (i) Fill the burette with solution X 1 (ii) Pipette 25cm 3 of solution X 2 into 250ml conical flask (iii) Titrate solution X 2 with solution X 1 until a pink colour just appear (iv) Record your results in table 1: TABLE 1 Final burette reading (cm 3 ) I II III Initial burette reading (cm 3 ) Volume of X 1 used cm 3 Calculations: (a) Calculate the average volume of solution X 1 used (b) Calculate the number of moles of Fe 2+ in 25cm 3 of solution X 2 used (c) If the ratio MnO 4 -: Fe 2+ is 1:5, calculate the concentration of MnO 4 ions in moles per dm 3 Procedure II: (i) Rinse the conical flask and refill the burette with solution X 1
(ii) Pipette 25cm 3 of X 3 into a clean conical flask (iii) Warm this solution to about 50 o C ( Note : Be accurate with temperature) (iv) Titrate the solution in (iii) above against solution X 1 from the burette to a pink colour (v) Record your results in table II. Calculations: (a) Calculate the average volume of X 1 used (b) Calculate the number of moles of : (i) Sodium nitrite in one litre of solution (Na = 23, N = 14, O = 16) (ii) Nitrite ions in 25cm 3 of solution X 3 used (iii) Moles of solution X 1 used (c) (i) Work out the approximate ratio Mno 4 -: NO - 2 (ii) Write down the ionic equation for the reaction between acidified manganate (VII) ions and nitrite ions 2. You are provided with solid M . You are required to: (i) Carry out test on solid M (ii) Record your observations and inferences accordingly. Procedure:- 1. (i) Dissolve solid M in 15cm 3 of distilled water. Divide the resulting solution into six portions.
You've reached the end of your free preview.
Want to read all 288 pages?