40. Solving a chemistry problem

22. An accurate weighing of hydrochlorothiazide 0.2584 g was dissolved in 20 ml of water and 25 ml of a 0.1 M solution of cerium sulfate was added. After 10 minutes, 10 ml of 5% potassium iodide solution was added and the solution was left for 30 minutes in a dark place. Calculate the volume of 0.1 M sodium thiosulfate solution used for titration of released iodine, if 25.32 ml of titrant was used for titration in the control experiment. The content of hydrochlorothiazide (M.m.=297.7) in the preparation was 99.8%. Justify the use of this method for the quantitative analysis of hydrochlorothiazide. Write the equations of chemical reactions.