“Chemical genie” experiment

How to make a genie from magnesium powder and crystal iodine

Do you think mir­a­cles only hap­pen in fairy tales? In this ex­per­i­ment you’ll see how to sum­mon a ge­nie in a chem­i­cal lab­o­ra­to­ry!

Safe­ty pre­cau­tions

Wear pro­tec­tive gloves and glass­es and work in a well-ven­ti­lat­ed room.

Warn­ing! Do not try this at home. Only un­der pro­fes­sion­al su­per­vi­sion.

Reagents and equip­ment:

  • mag­ne­sium pow­der;
  • crys­tal io­dine;
  • wa­ter;
  • test tube;
  • pipette.

Step-by-step in­struc­tions

Into the test tube, we sprin­kle mag­ne­sium pow­der and crys­talline io­dine in the ra­tio of 3:2. We add a few drops of wa­ter.

Pro­cess­es de­scrip­tion

Mag­ne­sium is cov­ered with an ox­ide film which pro­tects it from chem­i­cal im­pact, so it does not re­act with­out io­dine with­out out­side help. If a lit­tle wa­ter is added, a re­ac­tion be­gins with the for­ma­tion of mag­ne­sium io­dide. Gaseous io­dine will be re­leased in the form of a thick vi­o­let va­por, as the re­ac­tion is ac­com­pa­nied by a large re­lease of heat.

Io­dine dis­solves very poor­ly in wa­ter, but even this low sol­u­bil­i­ty is suf­fi­cient for the re­ac­tion:

I₂ + H₂O → HIO +HI

The hy­droiod­ic acid that forms dis­solves the ox­ide film on the sur­face of the mag­ne­sium and re­acts with the “bared” met­al.

MgO + 2HI → MgI₂ + H₂O