29. Solving a chemistry problem

58. In the absence of a standard silver nitrate solution in the laboratory, the determination of the halide ion in the analyzed sodium salt solution was carried out using a strong basic anion exchanger AV-17 in the OH form.
An aliquot of the analyzed solution with a volume of V(X) was passed through a chromatographic column with an anion exchanger in the OH form, and after washing the column with water, the collected eluate was titrated with a solution of hydrochloric acid with a molar concentration of c(HC1), using V(HC1) ml of titrant solution.
Write the equation for the ion exchange reaction between the anion exchanger (R-OH) and the analyzed solution passed through the anion exchanger, in molecular and ionic form. Using the data below, calculate the titer (g/ml) of the halide ion in the test solution.
Why is it not recommended to use the above method when analyzing solutions containing halides of metals such as aluminum and magnesium?
Halide ion Br
V(X), ml 5.00
c(HCl), mol/l 0.08710
V(HCl), ml 8.05