What Is the Hydronium Ion Concentration in a Solution Prepared

Multiple Choice

What is the hydronium ion concentration in a solution prepared by mixing 50.00 mL of 0.10 mol L^-1 HCN with 50.00 mL of 0.030 mol L^-1 NaCN? Assume that the volumes of the solutions are additive and that K_a = 4.9 × 10^-10 for HCN.

A) 1.5 × 10^-10 mol L^-1
B) 4.9 × 10^-10 mol L^-1
C) 1.6 × 10^-9 mol L^-1
D) 7.0 × 10^-6 mol L^-1