Making golden crystals

How to make gold crystals with just two solutions

Safe­ty pre­cau­tions

The sub­stances used in this ex­per­i­ment are tox­ic and high­ly dan­ger­ous to your health. Do not try this at home! Use only un­der pro­fes­sion­al su­per­vi­sion.

Reagents and equip­ment

  • hot so­lu­tion of potas­si­um io­dide;
  • hot so­lu­tion of lead ni­trate with acetic acid;
  • a bot­tle with a stop­per;
  • fun­nel.

Step-by-step in­struc­tions

Pour hot so­lu­tions of potas­si­um io­dide and lead ni­trate with acetic acid into a glass bot­tle. As the so­lu­tions cool, ob­serve the for­ma­tion of beau­ti­ful crys­tals re­sem­bling a gold­en snow­fall! Then close the bot­tle with a stop­per.

Process de­scrip­tion

The hot so­lu­tions of potas­si­um io­dide and lead ni­trate re­act to form lead io­dide, which is sol­u­ble in hot wa­ter. How­ev­er, as the so­lu­tion cools slow­ly, the lead io­dide be­gins to pre­cip­i­tate as beau­ti­ful gold­en crys­tals. Acetic acid is added in or­der to pre­vent the for­ma­tion of byprod­ucts. The crys­tal­liza­tion process of lead io­dide is called the “Gold­en Rain” ex­per­i­ment.

Safe and easy ex­per­i­ments are wait­ing for you in the MEL Chem­istry sub­scrip­tion!