How would one go about separating the following substances. It's review for my test.

Question

A solution contains Al3+, Ca2+, Fe3+
, and Ni2+
ions. Draw a flow chart that outlines the procedure
required to separate this mixture (use the back if you need more room)

Answer 1

There may be better, faster. and easier ways to do this but this is a fast write up, too. I can't do flow diagrams on this forum so take what I write and turn it into a flow diagram.
Add NaOH (but not a huge excess) to ppt Al, Fe and Ni. Ca is in the filtrate. To the ppt, add an excess of NaOH. That dissolves Al but not Fe and Ni. Add NH3 to dissolve the Ni(OH)2 and form the Ni(NH3)4^2+ but not the Fe(OH)2.
Done.

Answer 2

Thanks a lot Dr. Bob!