4. The student then titrated 25.0 mL of the same buffer with0.1115 M NaOH. The observed data is below. Hand draw a graph of thedata (on graph paper) and determine the concentration of the weakacid in the buffer? Vol of NaOH Added (mL) pH Vol of NaOH Added(mL) pH 0.00 4.91 11.00 10.32 1.00 4.97 12.00 10.99 2.00 5.04 13.0011.26 3.00 5.11 14.00 11.44 4.00 5.2 15.00 11.57 5.00 5.29 16.0011.66 6.00 5.4 17.00 11.73 7.00 5.53 18.00 11.79 8.00 5.72 19.0011.84 9.00 5.99 20.00 11.89 10.00 6.66 21.00 11.91
5. What is the buffer strength from question 3 and 4 (i.e., thetotal of [HA] and [A- ])? 6. If the pH of the buffer (before it istitrated) is 5.70, what is the pKa of the weak acid?
