How do I test for the contamination of water with iodide ions?

1 Answer
Nov 7, 2016

Answer:

Make solutions of #Pb(NO_3)_2(aq)# and #NaI(aq)#

Explanation:

#Pb^(2+) + 2I^(-) rarr PbI_2(s)darr#

Lead iodide is very insoluble, and precipitates from aqueous solution as a canary yellow solid. So treat the water from the pipe with #Pb(NO_3)_2(aq)# to see if precipitation occurs.

I propose that you test the reaction by mixing #Pb(NO_3)_2(aq)# with #NaI(aq)# so that the results of a positive test can be appreciated.

And now test the water from the pipes with sodium iodide in a separate reaction.