103. Solving a chemistry problem

An excess of magnesium complexonate was added to 25 ml of mercury(II) nitrate solution. 2.45 ml of an EDTA solution with a molar concentration of 0.05145 mol/l was used for titration of the released magnesium ions. Calculate for the initial solution: a) molar concentration; b) mass concentration; c) normal concentration in the chloride titration reaction; d) titer of mercury(II) nitrate with respect to chlorine.