Difference between revisions of "Synthesis of potassium trisoxalatoferrate(III) trihydrate"
(Created page with "K<sub>3</sub>[Fe(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>].3H<sub>2</sub>O (procedure by 'Endimion'[http://www.sciencemadness.org/talk/viewthread.php?tid=17764#pid224517]) '...") |
(Stuff) |
||
| Line 1: | Line 1: | ||
| − | K<sub>3</sub>[Fe(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>] | + | This procedure for the synthesis of potassium trisoxalatoferrate(III) trihydrate, K<sub>3</sub>[Fe(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>]·3H<sub>2</sub>O, is presented here: |
| + | ==Synthesis== | ||
(procedure by 'Endimion'[http://www.sciencemadness.org/talk/viewthread.php?tid=17764#pid224517]) | (procedure by 'Endimion'[http://www.sciencemadness.org/talk/viewthread.php?tid=17764#pid224517]) | ||
'''Equipment:''' | '''Equipment:''' | ||
| − | + | * two beakers (100, 250 cm<sup>3</sup>) | |
| − | + | * small graduated cyllinder or a pipette with 0.1 cm<sup>3</sup> precision | |
| − | + | * Büchner funnel with filter paper, hooked up to a Büchner flask | |
| − | + | * vacuum pump with rubber tubing | |
| − | + | * thermometer (-10 °C - 150 °C or similar) | |
| − | + | * glass rod | |
'''Chemicals:''' | '''Chemicals:''' | ||
| − | + | * Mohr salt | |
| − | + | * [[sulfuric acid]], 2 mol dm<sup>-3</sup> | |
| − | + | * aqueous solution of [[oxalic acid]] dihydrate, 10% | |
| − | + | * [[potassium oxalate]] monohydrate | |
| − | + | * [[ethanol]], conc. | |
| − | + | * distilled [[water]] | |
| − | + | * [[acetone]] | |
| − | + | * [[hydrogen peroxide]], 20% | |
'''Procedure:''' | '''Procedure:''' | ||
| − | Dissolve 2 g of Mohr's salt in 7 | + | Dissolve 2 g of Mohr's salt in 7 cm<sup>3</sup> of hot distilled water acidified with ~0.35 cm<sup>3</sup> of 2 M sulphuric acid. |
| − | Add 9.8 | + | Add 9.8 cm<sup>3</sup> of oxalic acid solution. Heat carefully to the boiling point. Stop the heating and wait for the yellow iron(II) oxalate to settle down. Decant the water and add 7 cm<sup>3</sup> of hot distilled water. Mix thoroughly and repeat the decanting. |
| − | Prepare a hot aqueous solution of potassium oxalate monohydrate (put 1.3 g of the salt in 4.5 | + | Prepare a hot aqueous solution of potassium oxalate monohydrate (put 1.3 g of the salt in 4.5 cm<sup>3</sup> of water). |
Add it to the iron(II) oxalate precipitate and mix the suspension. | Add it to the iron(II) oxalate precipitate and mix the suspension. | ||
| − | Slowly add 4 | + | Slowly add 4 cm<sup>3</sup> of hydrogen peroxide drop by drop while mixing with a thermometer, ensuring the temperature doesn't exceed 40 °C. |
| − | After that, heat to the boiling point and add 2.6 | + | After that, heat to the boiling point and add 2.6 cm<sup>3</sup> of the oxalic acid solution. The precipitate should dissolve. |
| − | Add 0.7 | + | Add 0.7 cm<sup>3</sup> more, drop by drop, while maintaining the temperature close to the boiling point. |
Filter the hot solution and let it cool down. | Filter the hot solution and let it cool down. | ||
| − | Start adding 5 | + | Start adding 5 cm<sup>3</sup> of ethanol, drop by drop. If crystals do not form, reduce the volume by boiling in the dark or leave it in the dark for several days. |
Filter off the crystals using a Büchner funnel and wash them with a 1:1 solution of ethanol and water. Repeat the washing using acetone. | Filter off the crystals using a Büchner funnel and wash them with a 1:1 solution of ethanol and water. Repeat the washing using acetone. | ||
| Line 47: | Line 48: | ||
'''Reactions involved:''' | '''Reactions involved:''' | ||
| − | + | :Fe<sup>2+</sup> + C<sub>2</sub>O<sub>4</sub><sup>2-</sup> → FeC<sub>2</sub>O<sub>4</sub>(s) | |
| − | + | :2 FeC<sub>2</sub>O<sub>4</sub>(s) + 6 K<sup>+</sup> + 4 C<sub>2</sub>O<sub>4</sub><sup>2-</sup> + H<sub>2</sub>O<sub>2</sub>(l) + 2 H<sup>+</sup> + H<sub>2</sub>O → 2 K<sub>3</sub>[Fe(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>]·3H<sub>2</sub>O(s) | |
| + | |||
| + | ==References== | ||
[[Category:Synthesis]] | [[Category:Synthesis]] | ||
[[Category:How-to]] | [[Category:How-to]] | ||
Latest revision as of 19:27, 21 February 2016
This procedure for the synthesis of potassium trisoxalatoferrate(III) trihydrate, K3[Fe(C2O4)3]·3H2O, is presented here:
Synthesis
(procedure by 'Endimion'[1])
Equipment:
- two beakers (100, 250 cm3)
- small graduated cyllinder or a pipette with 0.1 cm3 precision
- Büchner funnel with filter paper, hooked up to a Büchner flask
- vacuum pump with rubber tubing
- thermometer (-10 °C - 150 °C or similar)
- glass rod
Chemicals:
- Mohr salt
- sulfuric acid, 2 mol dm-3
- aqueous solution of oxalic acid dihydrate, 10%
- potassium oxalate monohydrate
- ethanol, conc.
- distilled water
- acetone
- hydrogen peroxide, 20%
Procedure:
Dissolve 2 g of Mohr's salt in 7 cm3 of hot distilled water acidified with ~0.35 cm3 of 2 M sulphuric acid.
Add 9.8 cm3 of oxalic acid solution. Heat carefully to the boiling point. Stop the heating and wait for the yellow iron(II) oxalate to settle down. Decant the water and add 7 cm3 of hot distilled water. Mix thoroughly and repeat the decanting.
Prepare a hot aqueous solution of potassium oxalate monohydrate (put 1.3 g of the salt in 4.5 cm3 of water).
Add it to the iron(II) oxalate precipitate and mix the suspension. Slowly add 4 cm3 of hydrogen peroxide drop by drop while mixing with a thermometer, ensuring the temperature doesn't exceed 40 °C.
After that, heat to the boiling point and add 2.6 cm3 of the oxalic acid solution. The precipitate should dissolve.
Add 0.7 cm3 more, drop by drop, while maintaining the temperature close to the boiling point. Filter the hot solution and let it cool down.
Start adding 5 cm3 of ethanol, drop by drop. If crystals do not form, reduce the volume by boiling in the dark or leave it in the dark for several days.
Filter off the crystals using a Büchner funnel and wash them with a 1:1 solution of ethanol and water. Repeat the washing using acetone.
Store it at a dark place (black plastic bottle).
Reactions involved:
- Fe2+ + C2O42- → FeC2O4(s)
- 2 FeC2O4(s) + 6 K+ + 4 C2O42- + H2O2(l) + 2 H+ + H2O → 2 K3[Fe(C2O4)3]·3H2O(s)
