Iodine diffusion

How can one see diffusion with the help of iodine?

Safe­ty pre­cau­tions

Warn­ing! Un­der adult su­per­vi­sion.

Equip­ment

  • re­leasable bag;
  • cop­per(II) sul­fate;
  • potas­si­um io­dide so­lu­tion;
  • starch so­lu­tion.

Step-by-step in­struc­tions

Mix cop­per(II) sul­fate and a so­lu­tion of potas­si­um io­dide in a re­leasable bag. Dip it into a glass of starch so­lu­tion. Ob­serve the so­lu­tion grad­u­al­ly turns blue.

Process de­scrip­tion

When cop­per(II) sul­fate and a so­lu­tion of potas­si­um io­dide are mixed, a re­dox re­ac­tion oc­curs, re­leas­ing io­dine. Io­dine has a prop­er­ty - it pass­es through some plas­tics, like one from which the re­leasable bag is made of. In this case, it hap­pens due to a process called dif­fu­sion.

This one and the oth­er safe ex­per­i­ments are wait­ing for you in the MEL Chem­istry sub­scrip­tion!

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