Can someone help me calculate the rate constant?

Question

The question says: Show your calculation of the rate constant for kinetic number 5.

The information I have is:

The reaction is first order in S2O8^2-, first order in I^-

Time taken for colour change: 62 Seconds

Initial concentration of I^- = 4*10^-2

Initial concentration of S2O8^2- = 7.67*10^-2

The S2O8^2- concentration in the reaction mixture at the time when the colour changes to blue : 7.50*10^-2

If more information is needed to find the answer then let me know cuz there are a few more values here (but I don't think they're needed)

Answer 1

This is a chemical question. You should repeat it in the category "chemistry".