Iron thiocyanates

Rhodan-baryum, n. barium thiocyanate, -eisen, n. iron thiocyanate, esp. ferric thiocyanate, iron(lll) thiocyanate, -eisenrot, n. ferric thiocyanate, iron (III) thiocyanate. 

The method can be used for the direct determination of the chloride ion content in precipitation samples within the 0.05-5 mg/L range. Chloride ions will replace the thiocyanate ions in undissociated mercury thiocyanate. The thiocyanate ions thus released react with ferric ions to form a dark red iron-thiocyanate complex. 

If the reaction between iron(III) and thiocyanate ions yielded an equilibrium concentration of 0.2 M for each of these ions, what would be the equilibrium concentration of the red iron-thiocyanate complex Hint The equilibrium constant can be found in the Background section. 

Some Mixed-Ligand Complexes with Iron Thiocyanate... 

As an example, we consider the equilibrium in aqueous solution between iron hexaquo complex cations and thiocyanate anions on the one hand and the blood red iron thiocyanate complex on the other which can be described in the following simplified manner ... 

Experiment 6.1 Iron(III) thiocyanate equilibrium If Fe " or SCN solutions are added to the pale orange dilute iron thiocyanate solution, it will turn red again in both cases. 

Coupling of Several Pairs of Quantities Predicting behavior becomes more difficult when dealing with a coupling not just between two pairs of quantities, but maybe between three such pairs. When a dissolved substance is added, the solvent is also added at the same time so that the potentials of all other dissolved substances change. We saw such behavior in Sect. 6.6 with the formation of the red iron thiocyanate complex (Experiment 6.1) ... 

Basavaiah K and Swamy JM (2001) Application of potassium dichromate and iron-thiocyanate in the spectrophotometric investigations of phenothiazines. II Farmaco 56(8) 579-585. 

Miller, M. Studies on Aqueous Solutions of the Iron Thiocyanates Dana Bogtrykkeri Copenhagen, Denmark,1937. 

Iron(III) chloride For the formation of the iron thiocyanate complex a solution of 5 g/L of FeClj 6H2O in a 19 1 mixture of acetone and distilled water is required. 

The velocity of the Fe(CNS)3-Na2S203 reaction depends on variations in the concentration ratios of iron thiocyanate thiosulfate, on the acid content, on the temperature. Aluminum, zinc, nickel, and especially arsenic retard the reaction. 

The presence of nitrites is to be avoided, since in acid solution they form nitrosyl thiocyanate NO CNS. This compound gives a red color (which will disappear on heating) very similar to that of the iron thiocyanate. ... 

The results obtained by CL quantification of lipid hydroperoxides in different types of oils were compared with those obtained for PV with the IT method and the iron thiocyanate method. By using the emulsion FI-CL procedure, a nonlinear response between CL signal and the concentration of oils from analyzed samples was obtained. This was explained by differences in turbidity between samples (due to the different amount of oils contained in the analyzed sample). When samples that contained the same quantity of oil but increased concentration of LOOH were used, the relationship between LOOH concentration and CL intensity was linear (r = 0.9908). 

Indicators for silver-halide precipitation titrations are of two types. The first react specifically when an excess of titrant becomes present immediately after the end point - for example, if a small amount of potassium chromate is added, it will react with excess silver ions to produce deep red silver chromate in neutral solutions (Mohi s method). In acid solutions, the silver is titrated with potassium thiocyanate (KCNS) solution (Volhard s method). Iron (III) ammonium sulfate solution is added and reacts with an excesss of thiocyanate to produce a deep red iron thiocyanate species. 

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