A gas mixture was passed at the rate of 2.50 L/min through a solution of sodium hydroxide for a total of 59.00 min. The SO2 in the mixture was retained as sulfite ion:
SO2( g) + 2OH¯ ( SO32- + H2O
After acidification with HCl, the sulfite was titrated with 5.15 mL of 0.002997 M KIO3:
IO3¯ + 2H2SO3 + 2Cl¯ ( ICl2¯ + 2SO42- + 2H+ + H2O
Use 1.20 g/L for the density of the mixture and calculate the concentration of SO2 in ppm.