a weak unknown monoprotic acid is titrated with a strong base. the titration curve is shown below. the plot shows ph as a function of naoh volume in milliliters. the y-axis represents the ph, ranging from 0 to 14 with the intervals of 2. the x-axis represents the volume, ranging from 0 to 50 milliliters with the intervals of 25. the curve slightly goes up from the ph equal to 1.6 and volume equal to 0 milliliters to the ph approximately equal to 4 and volume approximately equal to 24 milliliters, and then the curve rises sharply to the ph approximately equal to 10.5 and volume approximately equal to 26 milliliters. then the curve goes up slightly to the ph approximately equal to 11.5 and volume approximately equal to 50 milliliters. part a what is the ka for the unknown acid?