"Diffusion: mysterious movement” experiment

Amazing experiment with lead nitrate and potassium iodide

Mys­te­ri­ous move­ment and mag­i­cal ma­te­ri­al­iza­tion, all in one ex­per­i­ment!

Safe­ty pre­cau­tions

Wear pro­tec­tive gloves and eye pro­tec­tion.

Warn­ing! Don’t try to re­peat this ex­per­i­ment with­out a pro­fes­sion­al su­per­vi­sion!

Reagents and equip­ment:

  • lead ni­trate (1 g);
  • potas­si­um io­dide (1 g);
  • wa­ter (200 mL);
  • glass dish (1);
  • plas­tic tea­spoons (2).

Step-by-step in­struc­tions

Pour a cup of wa­ter into the glass dish. In­tro­duce the lead ni­trate and potas­si­um io­dide to the wa­ter on op­po­site sides of the dish from one an­oth­er. In a minute, the salts will dis­solve and a yel­low pre­cip­i­tate will form a stripe in the cen­ter of the dish.

Pro­cess­es de­scrip­tion

When lead ni­trate and potas­si­um io­dide dis­solve in wa­ter, they dis­so­ci­ate into ions. These ions don’t stay in one place – they grad­u­al­ly spread out through the whole dish in a process known as dif­fu­sion. When lead ions meet io­dide ions, lead (II) io­dide forms, ap­pear­ing as an in­sol­u­ble yel­low pre­cip­i­tate.

Try it