INORGANIC cHEMISTRY - IIi

Experiment 2

Principle

Fe₂O₃ + 6 Na₂C₂O₄→ 2Na₃[Fe(C₂O₄)₃]

Sodium Trioxalato Ferrate(III)

(Green Crystals)

Materials required

Chemicals Required:

Ferric Chloride(10 gm), NaOH (11.5 gm), Oxalic acid (12 gm)

Apparatus Required:

Beaker, Glass Road, Glass Funnel, Filter paper, Conical Flask.

1. Dissolve 10 gm of Ferric Chloride in 10ml of water.

2. Dissolve 7.3 grams of NaOH in 5ml of water.

3. To the solution of feric chloride. Add Sodium Hydroxide solution in small quantity, Resulting in the formation of Ferric Hydroxide.

4. Now filter the precipitates of ferric hydroxide and wash it several times with small quantities of hot water.

5. In another beaker dissolve 12 grams of oxalic acid in 50 ml of water.

6. To this solution add the pellets of Sodium Hydroxide (4 grams), Resulting in the formation of sodium oxalate.

7. Now add the washed hydrated ferric hydroxide to the hot Sodium oxalate solution with constant stirring by a glass rod.

8. Filter the solution and reject any residue if present. On the filter paper.

9. Concentrate the green filtrate in a silica dish on a water bath.

10. Green crystals of sodium ferric oxalate separates.

Calculation:

Molecular Weight of Ferric Chloride - 162.2 gm/mol

Molecular Weight Sodium Tri-oxalato ferrate(III) - 388.8 gm/mol

If 162.2 gm of Ferric Chloride gives 388.8 gm of Sodium Tri-oxalato ferrate(III)

Then 10 gm of Ferric Chloride gives ………….

Reference Material

Vogel’s textbook of quantitative Chemical Analysis.

Questions

1. What is the denticity of oxalate ion?

2. What is the oxidation state of Fe in this complex?

3. Explain primary and secondary valency of Fe in this complex.