A 500 ML Sample of 2

A 50.0 mL sample of 2.0 * 10^-4 M CuNO₃ is added to 50.0 mL of 4.0 M NaCN. The formation constant of the complex ion Cu(CN) ₃^2- is 1.0 * 10⁹. What is the copper(I) ion concentration in this system at equilibrium

A) 2.3 * 10^-14 M
B) 1.3 * 10^-14 M
C) 1.3 * 10^-13 M
D) 2.3 * 10^-13 M
E) None of the above