106Q3. K4Fe(CN)6 ??
Q1 Anhydrous Ferric chloride is prepared by ??
Q2 FeCl3.6H2O is actually ??
Q3 Ferrous and ferric ions may be distinguished by ?
Q4 Ferric ions are estimated by ?
Q5 Mohr Salt on oxidation with conc. HNO3 gives ?
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12 Answers
11Ans 1) Anhydrous iron(III) chloride may be prepared by union of the elements
2 Fe(s) + 3 Cl2(g) → 2 FeCl3(s)
Ans 2) The structure of FeCl3.6H2O normally consists of trans [Fe (H2O) 4 Cl 2] Cl . 2 H2O, though in strong H Cl it forms tetrahedral [ Fe Cl 4] -
1Ferrous and Ferric ions maybe distinguished by adding NaOH or NH4OH to their salt solutions which form green and reddish brown precipitate respectively.
Anhydrous FeCl3 can be prepared by the direct combination of Fe and Cl2,as mentioned by Tushar.
11Ans 3)
REAGENT NaOH K4Fe(CN)6
Fe 2+ green ppt White ppt turning blue rapidly
Fe 3+ red brown ppt Prussian blue ppt
K3Fe(CN)6 KSCN
Turnbull's blue ppt no colour
red brown colour deep red colour
(no ppt)
19where did u get all these ?
deserves a pink ....really good!! carry on !!!
13Q4) - Qualitative Estimation or Quantitative ??
I can tell qualitative, but quantitative....pata nahi...
Qualitatively estimating Fe3+ ions....
1) With K4[Fe(CN)6] ----> Ferri ferro cyanide (Prussian blue colouration)
2) With CNS- ------> Fe(CNS)3 (Red)
3) With CH3COO- -----> Fe(CH3COO)3 (Blood red)
24ok..i will give options for Q4 to reduce confusion
a)titrating against acidified KMnO4
b)Titrating against mohr salt soln
c)titrating against oxalic acid soln
d)first reducing ferric ions by stannous chloride and then titrating against a soln of acidified KMnO4