Determination of Fe from HCl extract of Plant Ash solution

Detection of Fe from the HCl extract of Plant Ash solution

 Presence of Fe(lll) ions is determined by Thiocyanate Test. 

  Principle:-

  It is a very sensetive test in which Fe(lll) ions convert to Fe(ll) ions when treated with Thiocyanate ions/ (SCN)- .

Experiment	Observation	Inference
To about 10 ml of HCl extract of Plant Ash solution , a drop of 5% Ammonium Thiocyanate is added.	The solution turns blood red immediately.	Blood red colour is formed due to the foation of a compound by Fe(ll) ions.   So, Fe is present in the given solution.

Reaction:

Fe(H2O)63+ + (SCN)- (aq) →Fe(SCN)(H2O)52+

Test 2

Experiment:

2 ml of acidic solution is heated in a test tube, to it 2% potassium ferrocyanide soln. is added.

Observation:

A purplish blue ppt. appears due to the formation of ferric ferrocyanide complex.

Inference:

Fe present in the given acid solution.

Reaction:

Fe(3+) + K4[Fe(CN)6]3-->Fe4[Fe(CN)6]3 +4K(+)