A Buffer Solution Is Made Such That the Initial Concentrations

Multiple Choice

A buffer solution is made such that the initial concentrations of lactic acid (HC₃H₅O₃ ) and the lactate ion (C₃H₅O₃-) are 0.600 M and 0.620 M, respectively.What is the resulting pH if 100.0 mL of 0.100 M potassium hydroxide is added to 0.500 L of the buffer solution? (The K_a of HC₃H₅O₃ is 1.4 * 10^-4.)

A) 3.81
B) 3.90
C) 2.75
D) 4.96
E) 3.85