identify the most likely sequence of steps in the mechanism. Bromonium ion formation, nucleophilic attack by water, tautomerization. Bromonium ion formation, tautomerization, nucleophilic attack by water. Nucleophilic attack by water, bromonium ion formation, tautomerization. Nucleophilic attack by water, tautomerization, bromonium ion formation.

Using the relationship M1V1 = M2V2 where M1 and M2 are the molar concentrations (mol/L or mmol/ml) and V1 and V2 are the volumes of the solutions, we can arrive at the following answer for the given problem:

15.0M (L of stock solution) =  2.35M (0.25L) *all volumes were converted to liters.

L of stock solution = (2.35*0.25)/15.0

Therefore, 0.0392L or 39.17 ml of stock solution is needed.