Question

3. A student followed the procedure of this experiment to determine the percent Naocl in a commercial bleaching solution that was found in the basement of an abandoned house. The student diluted 50.00 mL of the commercial bleaching solution to 250 mL in a volumetric flask, and titrated a 20-ml aliquot of the diluted bleaching solution. The titration required 35.46 ml of 0.1052M Na S,O3 solution. A faded price label on the gallon bottle read $0.79. The density of the bleaching solution was 1.10 g/ml. Refer to the post laboratory assignment calculations for h-j. a) Calculate the number of moles of s,o,required for the titration. b) Calculate the number of moles of Iproduced in the titration mixture.

Need help with B pls

Answer 1

Volume of commorcial = 50mL bleach solution Dilution made upto =250mL The reaction taking place during titration; ID Clo + 2H+ + 21- cit H₂O + Iz 2) Iz + 250 540 +21

The titration required 35.46mL of 0.1052m Nags₂O₃ 35. 46 mx x 0.1052 moly 3.7304 mmol of Naz S203 Na₂S2O 2Na+ + S203² - . 1 mol of Naz Szla produces 1 mol of Soh &. 3. 7304 mmol of Na₂S2% produces 3.7304 mmol of S₂03²- - Moles of 50% required = 3. 7304 103 mol 6 I +2407 → Sul² + 21- clear from the equation that 2 moles of Sz9?- require 1 mol of Iz : 3.7304 X163 mol " " 3.730440 2 7.8652 xlov mat of IZ 1 Moles of Iz required = 1.8652816 mol analysis was Thus the titration carried out.