35. Solving a chemistry problem

40. A 20.00 ml sample of the bleaching solution was diluted in a volumetric flask to 250.0 ml and 50.00 ml of this solution was titrated iodometrically using 21.16 ml of 0.1241 N. Na2S2O3 (feq=1). Calculate the concentration (g/l) of active chlorine in the initial solution.