Question

You wish to prepare 100 mL of 0.600 M HCl from concentrated HCl (12.85 M). You are provided with a 100 mL volumetric flask and a 10 mL graduated pipet with 0.00 line at the top and calibration lines each 0.1 mL. When filled to the 0.00 mL line this pipet would dispense 10.00 mL of solution when drained leaving only the final inside drop. At what volume reading on the pipet should you start dispensing the 12.85 M HCl to have the correct number of moles to give the 0.600 M solution when dispensed into the volumetric flask?

Answer 1

Because we need to dispense 4.7 mL, the volume reading in the pipet is the 5.3 mL line.

Step-by-step explanation:

First we use C₁V₁=C₂V₂ in order to calculate the required volume of concentrated HCl (V₁):

12.85 M * V₁ = 0.600 M * 100 mL

V₁ = 4.7 mL

So we need to dispense 4.7 mL of the concentrated HCl solution. The mark in the pipet that would contain that volume would be 10.0 - 4.7 = 5.3 mL