Now that you have determined the concentration of the base used to titrate the HCl in the micropipette, and you have recorded the volume of the HCl sample (5.00 mL) and the number of mL of base used, you can calculate the concentration of the HCl solution. Pop up the Data Sheet to get the number of mL of base used to titrate the HCl solution. First calculate the number of moles of base used (be careful about the volume units): moles base = (Vbase) (Mbase) Moles of base mol This is equal to the number of moles of HCl present in the 5.00 mL of HCL delivered to the flask.