Part A Preparation of Iron (II) Oxalate, FeC
1. 1.0 ml 2M sulphuric acid was added into 50.0 ml warm water, followed by 15g ferrous
2. 10% oxalic acid solution was prepared. Then, a solution of 10% oxalic acid (75.0 ml) was
added slowly with rapid stirring.
This step must be conducted in fume hood.
3. The mixture was gently heated until boiling.
4. Turn off the heat and brought the mixture to room temperature and wait the yellow
precipitate of ferrous oxalate to settle down.
5. The precipitate was removed by vacuum filtration. Washed it thoroughly with hot water
(3x10.0ml) followed by acetone (3x10.0 ml).
6. The product was dried in a desiccator and weighed. This product will be used to synthesised
potassium trioxalatoferrate(III) trihydrate.
Part B Preparation of Potassium Trioxalatoferrate(III) Trihydrate, K
1. A potassium oxalate solution was prepared by add 2.306 g of potassium oxalate monohydrate
in 10ml warm water.
2. Then, 1.125 g of iron(II) oxalate (product from Part A) was added into the potassium oxalate
3. The solution was heated and maintained the temperature at 40°C. 8 ml of hydrogen peroxide
was added dropwise (H
, 30% v/v) while the solution is stirred continuously. The solution
should contain a precipitate of ferric hydroxide.
This step must be conducted in
4. Then, the solution was heated until boiling.
5. 10% oxalic acid (5 ml) was drop wisely until the precipitate just dissolves. During the addition
of oxalic acid, the solution’s temperature should be maintained near the boiling point.
6. The hot solution was filtered by vacuum filtration and add ethanol (8 ml) to the filtrate. If
there are some crystals formed, re-dissolved those crystals by gentle heating and stir the solution
by using the glass rod.