Question

A study of the reaction of bromide ion with bromate ion under acidic conditions, gave the following data:

reaction time(s) [Br-](mol L-1)
0.0 1.50 x 10-2
90.0 3.49 x 10-3

5 Br-(aq) + BrO3-(aq) + 6 H+(aq) --> 3 Br2(aq) + 3H2O(l)

If the initial concentration of H+(aq) for the experiment is 0.100 mol L-1 and the initial rate is 5.00 x 10-5 M s-1, calculate the concentration of H+(aq) after 20.0 seconds of reaction time, assuming that there is a negligible change in the rate of reaction.