This liquid changes colors when shaken

The faster you shake it, the quicker it turns blue!

Warn­ing! Only un­der adult su­per­vi­sion.

Equip­ment

  • flask with warm wa­ter and stop­per;
  • glu­cose so­lu­tion;
  • sodi­um hy­drox­ide;
  • methy­lene blue dye.

Step-by-step in­struc­tions

Mix so­lu­tions of glu­cose, sodi­um hy­drox­ide, and methy­lene blue dye in a flask with warm wa­ter. The re­sult­ing so­lu­tion stays blue for some time, but then it turns col­or­less… But it eas­i­ly turns blue again: just shake the flask or pour the liq­uid into a glass!

Process de­scrip­tion

The sodi­um hy­drox­ide forces the methy­lene blue dye to re­act with the glu­cose, caus­ing it to lose its col­or. When the so­lu­tion is shak­en or poured, it be­comes sat­u­rat­ed with oxy­gen from the air. The dis­solved oxy­gen rapid­ly re­acts with the col­or­less dye, turn­ing it blue again. This can serve as the ba­sis for an amus­ing sci­ence trick, as the process can be re­peat­ed mul­ti­ple times with the same so­lu­tion!

A sim­i­lar ex­per­i­ment is in­clud­ed in the “Oxy­gen” set from the MEL Sci­ence sub­scrip­tion.