Does EDTA react with copper?
from EDTA, with the indicator being released from the copper ion. Note that the anion completely surrounds the cation, forming six coordinate covalent bonds to copper and a very stable complex. The bonding to the copper ion is nearly octahedral.
What is the colour of copper EDTA complex?
On addition of EDTA (ethylene-diaminetetraacetic acid), copper- EDTA complex ions (Cu(EDTA)2-) are formed, which are pale blue (far right).
What is Cu EDTA?
Cu(II)-EDTA Organic compounds that coordinate metal ions into circular structures (chelate circles) are called chelating reagents. Ethylenediamine tetraacetic acid (EDTA), which has many coordinated atoms, forms a very stable chelate between one molecule of EDTA and metal ion.
What is stoichiometry of Cu EDTA complex?
The resulting metal–ligand complex, in which EDTA forms a cage-like structure around the metal ion (Figure 9.26b), is very stable. The actual number of coordination sites depends on the size of the metal ion, however, all metal–EDTA complexes have a 1:1 stoichiometry.
What are the indicators used in the estimation of copper by EDTA?
Remarks: The copper-murexide complex is pure yellow, but the color at the starting point of the titration is greenish depending on the amount of copper present. The green is the mixture of yellow (indicator complex) and blue (copper-tetramine complex).
Why the estimation of copper is known as iodometric titration?
In acid solution practically all oxidizing agents will oxidize iodide ion to iodine quantitatively. The iodine formed in the reaction can then be titrated by means of a standard sodium thiosulfate solution. This type of indirect titration is given the general name of iodometry.
Why can copper form complex ions?
More than one ligand can bind to a transition metal ion to form a complex ion. The copper ion, Cu2+ (aq), in aqueous solution, forms a blue complex ion, [Cu(OH2)6]2+, with 6 water molecules. The blue complex is the cause of the blue colour of copper sulfate solution.
What is the colour of the copper?
Copper is a reddish brown color that resembles the metal copper.
Which indicator is used in estimation of copper?
Copper(II) or Copper(II) and iron(III) in a mixture are determined by titration with EDTA (disodium salt) solution as complexometric reagent at pH 4.0 using potassium thiocyanate-p-anisidine as an indicator.
Why does NI 2 form complex with EDTA?
In acid solution (pH 2) the nickel(II)-EDTA complex exists in a form in which one carboxylate arm is protonated and replaced in the co-ordination sphere by a water molecule, while in neutral solution (pH 6–7) a temperature-dependent equilibrium exists between two forms both probably six-co-ordinate, one containing …
What is the indicator used in estimation of copper?