Titration of Na2CO3 with HCl. You may want to record your answers in the Data Collection section of your lab manual for use during the lab. (pKa1(H2CO3) = 6.352, pKa2(H2CO3) = 10.329). What are the first and second equivalence volumes (Veq1 and Veq2) when 20.00 mL of 0.10 M Na2CO3 is titrated with 0.20 M HCl?