三草酸合铁酸钾的制备.ppt

Synthesis of Potassium Trioxalatoferrate
1242617~1242624
Objective :
1. To learn basic operations such as synthesis, characterization and chemical analysis of pounds.

2. To develop analytical and problem solving skills through the practice of experimental design

3. To learn the synthesis of Potassium Trioxalatoferrate (lll)
Potassium Trioxalatoferrate(III)
Chemical formula: 2K3·[Fe(C2O4)3] ·3H2O
Color:bright green
Solubility:
Water(0℃ ;100℃ )
Ethanol(hard)
Stability:
110℃ it loes its crystal water
230℃ it is posed
Usage
As a chemical photometric agent, since it is sensitive to light and poses to yellow color when exposed to light:
2K3·[Fe(C2O4)3]·3H2O→
3K2C2O4 + 2FeC2O4 + 2CO2↑+ 6H2O
As an effective catalyst for anic reactions
PRINCIPLES
STEP 1 :
Combine ammonium ferrous sulfate and oxalate acid
(NH4)2Fe(SO4)2 ·6H2O+H2C2O4→FeC2O4·2H2O↓
+ (NH4)2SO4+H2SO4+4H2O
STEP 2:
With the presence of excess amount of oxalate anions, oxidation of ferrous oxalate by hydrogen peroxide produces potassium trioxalatoferrate and ferric hydroxide:
6FeC2O4·2H2O+3H2O2+6K2C2O4 → 2Fe(OH)3↓
+ 2K3·[Fe(C2O4)3]+ 12H2O
Step 3 :
Fe(OH)3 can be converted to trioxalatoferrate pound with proper amount of oxalate acid
2Fe(OH)3+3H2C2O4+3K2C2O4→
2K3·[Fe(C2O4)3] ·3H2O
Step 4 :
The product crystallizes after the addition of ethanol.
The overall chemical equation:
2FeC2O4·2H2O+H202+3K2C2O4+H2C2O4
===2K3[Fe(C2O4)3] ·3H2O
Equipment :
Platform balance ,filter flask, thermostatic water bath , Buchner funnel , ph test paper , alcohol burner
Chemicals:
ammonium ferrous sulfate , sulfuric acid(3mol/l), saturated oxalic acid, saturated potassium oxalate, 6%hydrogen peroxide , 95%ethanol,
potassium nitrate  solid
Procedures:
(NH4)2Fe(SO4)2 ·6H20 in 50ml beaker
Add 3 drops of 1mol/L H2SO4
Add 10mL H2O
Heat
pletely
Add H2C2O4
heat in a boiling water bath
precipitate
Add 25ml H2O
Remove the solution by tilt-pour process
Repeat 3 times