A buret (initial and final buret reading were 2.20 mL and 11.86 mL) was used to deliver a sample of 2.1E-5 M stock dye into a 25.0 mL volumetric flask. The dye was then diluted with water to exactly 25.0 mL. Calculate the molarity of the resulting solution.

Answer 1

You delivered from the buret exactly 11.86-2.20 = ?? mL of the dye.
Final concn then = 2.1E-5 x (??mL/25.0 mL) = xx M