Example:A solution contains 0.10molL-!Fe3+and 0.10mol-L-1 Ni2+ions.You wish to remove Fe3+as completely as possible by precipitating it as an insoluble hydroxide and leaving Ni2+ions in solution. What's the pH range of the solution you must control? Strategy: n K Preiptate be:cOHr)≥yc.Mr） K Precipitate complete:(H)101 Example：A solution contains 0.10mol·L-1 Fe3+ and 0.10mol·L-1 Ni2+ ions. You wish to remove Fe3+ as completely as possible by precipitating it as an insoluble hydroxide and leaving Ni2+ ions in solution. What’s the pH range of the solution you must control? Strategy: n 5 sp 1.0 10 (OH ) - - x  K Precipitate completes: c n n o sp (M ) (OH ) + -  c K Precipitate begins: c