How to grow and shrink gummy candies

How to resize gummy candies

Is it pos­si­ble to change the size of a gum­my can­dy? It sure is! Find out how in this cool video!

Safe­ty pre­cau­tions

Per­form this ex­per­i­ment only un­der adult su­per­vi­sion.

Reagents and equip­ment

  • 2 glass­es;
  • gum­my can­dies;
  • wa­ter;
  • sat­u­rat­ed sodi­um chlo­ride so­lu­tion (4 tbsp per cup of boil­ing wa­ter).

Step-by-step in­struc­tions

Dis­trib­ute a few gum­my can­dies among two glass­es. Fill one glass with wa­ter, and the oth­er with a sat­u­rat­ed sodi­um chlo­ride so­lu­tion (4 ta­ble­spoons per cup of boil­ing wa­ter). 10 hours lat­er, you will see a sig­nif­i­cant dif­fer­ence be­tween the con­tents of the glass­es. The gum­mies in wa­ter have grown, and the can­dies in the salt so­lu­tion have de­creased in size!

Process de­scrip­tion

Gum­my can­dies con­tain gelatin, a poly­mer of nat­u­ral ori­gin that, due to its struc­ture, can ab­sorb and re­tain wa­ter. Wa­ter mol­e­cules are rel­a­tive­ly small and can seep into the in­ter­molec­u­lar spa­ces in the gelatin. Once in the gelatin, they re­main there due to the for­ma­tion of hy­dro­gen bonds and so, gelatin swells in the wa­ter!

The re­verse hap­pens in a ta­ble salt so­lu­tion: the wa­ter in the can­dies is pulled into the so­lu­tion. The wa­ter mol­e­cules are at­tract­ed by the ex­cess of ions in the salt so­lu­tion, and aban­don the gelatin to sur­round the ions in a “coat” of sorts. Wa­ter mol­e­cules are struc­tured such that they have two poles: one pos­i­tive­ly charged, one neg­a­tive­ly charged. Each wa­ter mol­e­cule ori­ents it­self so that the pole fac­ing the ion it in­ter­acts with has the op­po­site charge to that of the ion it­self. As a re­sult, can­dies shrunk in the ta­ble salt so­lu­tion!