Diluting a solution: How would you prepare 500.0 mL of 0.2500 M NaOH solution starting from a concentration of 1.00 M?
Strategy: The problem gives initial and final concentration `(M_(i) and M_(f))` and final volume `(V_(f))` and asks for the initial volume `(V_(i))` that we need to dilute.
Write the dilute formula (2.17) and rearrange it to give the initial volume.

Explanation

According to Equation `(2.17)`
`M_(i)V_(i)=M_(f)V_(f)`
or `V_(i)=(M_(f)V_(f))/V_(i)`
Substituting the known values into the right side of the equation:
`V_(i)=((0.2500 M)(500.0 mL))/((1.000 M))`
`=125.0 ML`
In practice, bilution is carried out as follows: the valume to be diluted is withdrawn using a calibrated tube called a pipet, placed in an empty volumetric flask of the chosen volume, and diluted to the calibration mark on the flask.
In this particle case, we need to place `125.0 mL` of `1.000 M NaOH` solution in a `500.0 mL` volumeritc flask and fill to the mark with water.