Golden rain - ionic bonding demo

Before I even try to teach ionic equations I check to see if my students have picked up any misconceptions about how ions behave in aqueous solution.
The precipitation of lead iodide from a solution of potassium iodide and lead nitrate is so dramatic and engaging that I use it both with my 11-14 and 16-18 year old students. The younger students see this reaction when I’m introducing ionic bonding. I show the reaction again to my older students and ask them to sketch particle diagrams to explain what they are seeing.
Thankfully, the ‘seen it before’ mentality is easily avoided with this reaction - the ‘golden rain’ demonstration is a stunning suspension of glistening yellow crystals.
Read the article that accompanies this video in the January 2015 issue of Education in Chemistry at rsc.li/EiC115ec
This is part of the Education in Chemistry Exhibition Chemistry series: chemistry demonstrations to capture your students' imaginations: rsc.li/EiCExChem

[@crekrift5061]

How do you dispose of the end products?

[@leanderwyss6395]

nice video! Thanks

[@Rat656]

Actually golden rain is also of double meaning, isn't it? :> Nice demonstrantion, cheers

[@prajakta6138]

I do this .I take potassium iodide and lead nitrate .bt after heating ,there is no effect.only yellow ppt.is seen.not dissolved form of the reaction as you shown.

[@Justin_Martin]

This is awesome 🇺🇸👑💕

[@inhkhoi16]

excuse me , I did this in my chemistry class but it didn't work I don't know why . my HCl is not 1M it is pure HCl and my teacher didn't tell me what to do to made it so I hope that you will give me some tips . And also I put a lot of Pb(no3)2 so I wonder will that effect my project.

[@declan.fleming]

+Dino mon the HCl isn't that important .. it's only there to remove any carbonate precipitate impurities if you get a bit of white cloudiness in the background solution. I'd say c.HCl would be overkill :)

[@matinannaji602]

Định Khôi why use HCl. Just Pb(NO3)2 and KI will suffice, resulting in PbI2

[@ivanjaygacula2432]

How long it takes to be able to see the golden crystals after heating? I need an exact time. Thank you

[@declan.fleming]

depends on exactly how hot you made it and the ambient temp (how quickly you cool again). You can always boost the process by actively cooling the solution but the faster you cool the smaller the resulting crystals will be.

[@Kyle-sw8sh]

I've done this demonstration in class a bunch before. I suggest having a preheated/cooled sample ready to pull out for some "Martha Stewart cooking magic" if you plan on doing this for a demonstration. That way if you are running it multiple times for different classes, you will always have a sample that is in the active cooling/recrystalization phase