[iknowashtron]

From 40.0 mL of a 2.00 mol/L solution, the volume is brought to 200 mL with distilled water and then 40.0 mL of the resulting solution is isolated. To this new volume, the procedure described above is applied 19 times more. What will be the final concentration of the solution obtained?

I know how to calculate the concentration, but I'm not sure what to do here.

Thank you in advance!

[iknowashtron]

actually I think I figured it out, is 0,4x(40/200)^19 = 2,1x10^-14 the right answer?

[Borek]

Approach is OK, haven't checked the exact number.  It is pretty easy to miss (or add) one dilution in such cases.