Molar absorptivities of Nickel and Cobalt with 8-quinilinol are εCo = 3529 and εNi = 3228 at 365 nm, and εCo = 428.9 and εNi = 0 at 700 nm. Calculate concentration of nickel and cobalt in solution that gave Abs = 0.617 at 365 nm and Abs = 0.0235 at 700 nm

For the extraction of a metal ion with a metal chelator, by how many units will the pH change if the distribution ratio, D, changes from 0.060 to 100.0? Assume that the concentration of the ligand in the organic phase, [HL]org, will remain constant and that n = 2. ApH = units

25.00 mL 0.01000 M Ni2+ is titrated with 0.01000 M EDTA in a solution buffered topH 5.0. Given that the formation constant for the Ni-EDTA (NiY2–) chelate is4.2 x 1018 and the 4 value at pH 5.0 is 3.54 x 10–7. Explain briefly why EDTA is an important reagent used in complexometrictitrations.