Testing the effect different pHs have on the rate of reaction

On the second day we started by deciding to test the time that a bathbomb took to disolve in different ph solutions. The results are as follows:
Using sodium hydroxide to make the water alkaline:
time taken to dissolve = 132 seconds, pH of solution before = 9 and the pH afterwards = 8Using sulphuric acid to make the water acid:time taken to dissolve = 137 seconds, pH of solution before = 3 and the pH afterwards = 5To increase the reliability of the results (and test for patterns) we made the solution more acidy by adding more sulphuric acid:time taken to dissolve = 111 seconds pH before = 11 and the pH afterwards =8We had already tested the acidity of the bath bombs used, pH 7, neutral. Looking at the results we can therefore conclude that the bath bombs somewhat neutralise each solution; the strength of the alkaline decreases after the bath bomb has dissolved as did the strength of the acid solution.