Well you are testing for these cations by using:
1) NaOH (aq) first dropwise then in excess
2) NH3 (aq) first dropwise then in excess
3) KI (aq)
And you are testing for Pb, Ca and Cu and Fe
What would these do to the 4 cations?
Any colour changes or odours or other observations?
I found that
NaOH and Cu gives a Blue ppt turning black on heating
NH3 and Cu gives a Blue ppt turning deep blue in excess
NaOH and Fe gives A dirty green ppt turning brown on exposure to air and insoluble to excess.
NH3 and Fe gives a dirty green ppt and turns brown in air insoluble in excess.
KI i don't know what it gives.
The rest i can't seem to find especially the KI tests.
Thanks for any help.