A 500-ML Sample of 2

Multiple Choice

A 50.0-mL sample of 2.0 × 10^-4 M CuNO₃ is added to 50.0 mL of 4.0 M NaCN. Cu⁺ reacts with CN^- to form the complex ion Cu(CN) ₃^2-: What is the concentration of CN^- at equilibrium?

A) 6.0 × 10^-4 M
B) 1.0 M
C) 4.0 M
D) 2.0 M
E) none of these