M.Sc.

       Choline chloride / tartaric acid room temperature ionic liquid was prepared and the obtained phase diagrams of the mixture showed eutectic point at 5 ^oc. The ionic liquid showed a conductive properties, high density and low PH values. Secondly, the dissolution of Co₃O₄, CrO₃, NiO, CuO, and ZnO. Were studied and found   soluble in choline chloride / tartaric acid ionic liquid as their solubilities were determined by measuring the dissolved metal by atomic absorption from room temperature up to 100 ^oc.

          Chromium (III) complexes were prepared from sulphur containing ligands; Potassium alkyl xanthate, (PAX), these complexes were:

1- Tris (methylxanthato) chromium (III) complex Cr(mex)₃.

2- Tris (ethylxanthato) chromium (III) complex    Cr(etx)₃..

3- Tris (isopropylxanthato) chromium (III) complex Cr(prx)₃.

4- Tris (butylxanthato) chromium (III) complex   Cr(bux)₃.

5- Tris (hexylxanthato) chromium (III) complex   Cr(hex)₃.

   This thesis falls into three main chapters. Chapter I deals with a general survey of literature which discusses an introduction for chromium and vanadium (discovery, valances, uses, availability and toxic effects);also it includes the different techniques used for there determination.Focus was made on the determination of chromium and vanadium ions using spectrophotometric method in various different biological,industrial, drinking and sewage water samples.