Lead Iodide Precipitate

MEDIA NOTES:

LightingA	ON: FLUOR CHALKBOARD [ OFF: FRONTFLUOR 2000W DOWNLIGHT ]
LightingB	ON: DOWNLIGHT [ OFF: FLUOR FRONTFLUOR CHALKBOARD 2000W ]
Camera	Primary: CAM1 Secondary: CAM4 [ CAM2 CAM3 ]
P(oint) O(f) I(nterest)	Location 3, 1 liter beaker of colorless solution, becomes yellow when second liquid is added
Notes	1 liter beaker shot should be close to include only beaker if possible
Story	A solution is added to a colorless solution in a beaker. A bright yellow precipitate forms.
Preview	MOVIE [ 1 2 ] ... PICTURE [ 1 2 3 ]

Disclaimer

This documentation is intended ONLY for internal use by UCB CCHEM Demo Lab staff. General safety information is given elsewhere. Specific safety information may be missing from the following text. Safety information shown is not intended to be exhaustive, therefore, readers are warned to thoroughly research all aspects, safety and otherwise, of the experiments described here.

In additional to general Personal Protection Equipment, Demo Lab staff will always wear hearing protection when participating in, or working in the same room as, the preparation, transportation, performance, and recovery of any experiment that is intended to or CAN explode or produce a fireball.

Demo Lab Notes - see revision of 2007 below

Pb(NO₃)₂(0.01M)+2NaI(1M) --(precip)--> PbI₂+2NaNO₃
(~500ml TV)
Start with 1000 ml TF beaker containing 500 ml dilute 0.01M lead nitrate.
For demo, add slowly, stirring with glass rod, about 10 ml 1M NaI (or KI). Observe precipitate.

Rev. 20050825

Revision of Prof. Boering, Fall 2007

To a relatively large diameter test tube (sufficient for ~ 25+ ml), add 0.5 ml 1.0M Pb(NO₃)₂
Dilute this to total volume ~4 ml
To this, add 1 ml 1.0M KI solution, a brilliant yellow precipitate will form
Allow to stand a few minutes, then filter with medium filter paper
Collect the supernate in another test tube
To the supernate, add 1 or 2 drops of 1.0M KI, do not disturb or mix
(revision needed? separate aliquots, and possibly solid lead nitrate needed?) Allow the precipitate to settle some, then add 1 or 2 drops of 1.0M Pb(NO₃)₂ to the same solution, also do not mix

Rev. 20071002