Assume that you have 15ml of 2.5M potassium hydroxide but only have concentrated bottle of 16M strength. How would you obtain this
Do you mean you hav 16M KOH but you need 15 mL of 2.5M? Then
c1v1 = c2v2
2.5*15 = 16*v2
v2 = ?
You want (2.5*15/16) mL of the 16 M stuff and add water to a total of 15 mL.