An acetate buffer solution is prepared by combining 50 mL of 0.2M acetic acid, HC₂H₃O₂ (aq), and 50 mL of 0.2M sodium acetate, NaC₂H₃O₂ (aq). A 5.0 mL sample of 0.1M NaOH (aq) is added to the buffer solution. Which of the following is the correct pairing of the acetate species present in greater concentration and of the pH of the solution after the NaOH (aq) is added (the pKa of acetic acid is 4.7)?
a) C₂H₃O₂⁻, pH > 4.7
b) HC₂H₃O₂, pH < 4.7
c) C₂H₃O₂⁻, pH < 4.7
d) HC₂H₃O₂, pH > 4.7