Ombaka, Ochieng2020-10-262020-10-262019International Journal of Development and Sustainability Volume 8 Number 92186-8662https://www.researchgate.net/publication/338699034http://repository.chuka.ac.ke/handle/chuka/4843A simple, rapid and reasonable selective Complexometric technique for nickel (II) determination using some selected hydroxytriazene as a metallochromic indicator is reported in the present study. The colour change at the end point was from greenish-yellow/yellow to colourless with sharp end point. The pH ranges were 9.3-9.7, 9.0-9.5, 8.5-9.0, 8.0-8.5 while temperature ranges were 25-60, 25-60, 25-60, 25-50 and 25-50 0C for reagent (i), (ii), (iii), (iv), and (v) respectively. Nickel(II) was determined accurately up to concentration as low as 3.0x10-3M for reagents (ii), (iv), and (v)) while for reagents (i) and (iii) the concentration range could be even lowered to 1.0x10-3M for the determination of nickel (II). The ions such as Cl-, Br-, CH3COO-, CO32-, PO43-, SO42-, C2O42-, S2O32-, NO2-, SO32-, S2-, HPO42-, F-, NO3, WO42-, MO7O246-, I-, NH4+, Na+, K+ did not show any interference in the determination of nickel (II) even when they were present in tenfold excess. Ba2+, Mg2+, Ca2+, were tolerated up to five-fold excess. However Mn2+, Pb2+, Hg2+, Sn2+, Th4+, Cd2+, Co2+, Cu2+,Zn2+, interfered even at equivalent amount. The method was used to determine nickel in its synthetic alloy with maximum relative error of 0.78 when using secondary masking agent.enHydroxytriazenesNickelComplexometric TechniquesSynthetic Nickel AlloySecondary Masking AgentForeign IonsColour ChangeArticle