After performing Experiment 3, you have determined that your second equivalence point occurred after adding 42.50 mL of 0.1000 MHCl. Assuming that you dissolved your unknown sample in 100.00 mL of water, calculate the pH of the solution after 17.50 mL of HCl has been added? (Note: Kw = 1.00 x 10-14, Ka1= 4.44 x 10-7 and Ka2= 4.69 x 10-11) Report your pH to two significant figures.