1. Hydrogen peroxide reacts with thiosulfate ion in slightlyacidic solution as follows:

H₂O₂ + 2S₂O₃^2?+ 2 H⁺? 2H₂O + S₄O₆^2?

The reaction rate is independent of the hydrogen ionconcentration in the pH range 4 to 6. The following data wereacquired at 25 ?C and pH 5.0. Initial concentrations:[H₂O₂] = 0.036 mol/L,[S₂O₃^2-] = 0.0204 mol/L

(a) What is the overall order of the reaction?

(b) What is the rate constant?

No information was given for [H2O2] for the course ofthe reaction

2. For the reaction, where M is an inert gas atom (such as He orAr),

O + NO + M ? NO₂ + M

The rate constant exhibits the following temperaturebehavior:

at 300 K, k = 6 ? 10⁹L²mol^?2s^?1; at 1000 K, k = 3 x10¹⁰ L²mol^?2s^?1.

Determine the activation energy and the prexponential factorusing the Arrhenius equation.

Time (min) [SO3-] (mol/L) 16 36 43 52 10.30 5.18 4.16 3.13