SUMMARY
The efsects of p H and heating during the preparation of 51Cr-J-Chromium is an element with unique characteristics due to its coordination tendency. When a Cr (111) salt is dissolved in water, chromium is present as an hexaquo complex [Cr(H,0),l3+. This complex is potentially an acid and the equilibrium will de displaced to the right by heating :Simultaneously the process of olation is promoted leading to the formation of polynucleate complexes consisting of chains of Cr(II1) ions linked by bridging hydroxide groups :