# Reaction rates

## Homework Statement

Peroxydisulfate ion reacts with the iodide anion according to reaction 1:

S2O82- + 3 I-⇔ 2 SO42- + I3-

The amount of I3- formed can be determined by adding a known amount of SsO32- and allowing it to react according to reaction 2:

2 S2O32- + I3- ⇔ S4O62- + 3I-

If starch is added, any excess I3- will react to form a blue-black I2 complex. The formation of this complex indicates the completion of reaction 2. The rate of reaction 1 can be determined by the following equation where t is the elapsed time from the addition of the last component to the formation of the blue-black starch, I2 complex.

rate = 1/2 [S2O32-]/t

(1) what would happen to the time and the rate in equation 1, if more S2O32- were added, and all other conditions remained the same?

## The Attempt at a Solution

The thiosulfate ion only applies to reaction 1, therefore, I assumed that the time would be constant and the rate would increase; however, I need help understanding my initial rationale. Thanks!