A test for completeness of electrodeposition of Cu from a solution of Cu 2 (aq) is to add NH 3 (aq) A blue color signifies the formation of the complex ion Cu(NH 3 ) 4 2 (K f 1 1 x 10 13 ) Let 250 0 mL of 0 1000 M be electrolyzed with a 3 512 A current for 1368 s At this time, add a sufficient quan...

To determine whether the blue color should appear we need to calculate the concentration of CuNH342 ...

A test for completeness of electrodeposition of Cu from a solution of Cu 2+ (aq) is to

Question:

A test for completeness of electrodeposition of Cu from a solution of Cu²⁺(aq) is to add NH₃(aq). A blue color signifies the formation of the complex ion [Cu(NH₃)₄]²⁺ (K_f = 1.1 x 10¹³). Let 250.0 mL of 0.1000 M be electrolyzed with a 3.512 A current for 1368 s. At this time, add a sufficient quantity of NH₃(aq) to complex any remaining Cu²⁺ and to maintain a free [NH₃] = 0.10 M. If [Cu(NH₃)₄]²⁺ is detectable at concentrations as low as 1 x 10^-5 M, should the blue color appear?