Chapter 6, Problem 114IAE

The amount of ozone, O_2,in a mixture of gases can be determined by passing the mixture through a solution of excess potassium iodine, KL Ozone reacts with the iodide ion as follows:
${\text{O}}_{\text{3}}\left(\text{g}\right){\text{ + 3I}}^{-}\left(\text{aq}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{I}\right)\to {\text{ O}}_{\text{2}}\left(\text{g}\right){\text{ + I}}_3{}^{-}\left(\text{aq}\right)+2{\text{H}}^{-}\left(\text{aq}\right)$
The amount Of produced is determined by titrating with thiosulfate ion,
${\text{I}}_3{}^{-}\left(\text{aq}\right)+{\text{2S}}_{\text{2}}{\text{O}}_{\text{3}}^{\text{2-}}\left(\text{aq}\right)\to {\text{ 3I}}^{-}\left(\text{aq}\right)+{\text{S}}_4{\text{O}}_{\text{6}}^{\text{2-}}\left(\text{aq}\right)$
A mixture of gases occupies a volume of 53.2 L at 18 °C and 0.993 atm. The mixture is passed slowly through solution containing an excess of KI to ensure that all the ozone reacts. The resulting solution requires 26.2 mL of 0.1359 MNa₂S₂O₂ to titrate to the end point. Calculate the mole fraction of ozone the original mixture.