What concentration of NH3 is needed to lower the Cu2+(aq) to 6.4 x 10-14M in a solution that was originally 1.43 x 10-4 M in Cu2+(aq)? Assume that there is no volume change as NH3 is bubbled through the solution. (Kf for [Cu(NH3)42+] = 5 x 1012)
0.0771 M
0.0725 M
0.145 M
0.109 M
0.307 M