What Is the Magnitude of the Change in PH When

Multiple Choice

What is the magnitude of the change in pH when 0.005 moles of HCl is added to 0.100 L of a buffer solution that is 0.100 M in CH₃CO₂H and 0.100 M NaCH₃CO₂? The K_a for acetic acid is 1.8 × 10^-5.

A) 0.00
B) 0.20
C) 0.47
D) 1.30