The metal ion M2+ in ammonia, NH3 forms the complex ion M(NH3)62+ (Kf = 5.1x108). Calculate the M2+ concentration when the equilibrium concentrations of NH3 and M(NH3)62+ are 0.074 and 0.22 M respectively

Question

The metal ion M2+ in ammonia, NH3 forms the complex ion M(NH3)62+ (Kf = 5.1x108).  Calculate the M2+ concentration when the equilibrium concentrations of NH3 and M(NH3)62+ are 0.074 and 0.22 M respectively

DrBob222 · Answer

M^2+ + 6NH3 ==> [M(NH3)6]^2+ Write the Kf expression for the above reaction, plug in the equilibrium concentrations of NH3 and the complex and solve for (M^2+). This is a simple one to do.