A certain classification test calls for 5 mL of 1.2 M NaOH. The only concentration of NaOH solution available is 3.0 M. Describe how you would make the quantity that you need of the 1.2 M NaOH solution.

Question

A certain classification test calls for 5 mL of 1.2 M NaOH.  The only concentration of NaOH solution available is 3.0 M.  Describe how you would make the quantity that you need of the 1.2 M NaOH solution.

DrBob222 · Answer

5 mL x 1.2M = XmL x 3.0M
X = (5x1.2/3) = 2.0 mL
Pipet 2.0 mL of the 3.0M NaOH and dilute to the mark in a 5.0 mL volumetric flask. If a 5.0 mL volumetric flask is not available, you could pipet 4.0 mL of the 3.0M NaOH into a 10 mL volumetric flask and make to the mark.