Elephant's toothpaste

One of the most im­pres­sive chem­i­cal ex­per­i­ments. Looks like a vol­cano of foam.

Step-by-step in­struc­tions

Take a tray and a glass. Pour 50 ml of a 30% so­lu­tion of hy­dro­gen per­ox­ide into the glass, add a few drops of dish­wash­ing liq­uid and 2 g of food col­or­ing. Stir the so­lu­tion to make the food col­or­ing dis­solve bet­ter. Add 50 ml of a con­cen­trat­ed so­lu­tion of potas­si­um io­dide, and watch the “vol­cano of foam”.

Pro­cess­es de­scrip­tion

When hy­dro­gen per­ox­ide breaks down, wa­ter and oxy­gen are re­leased. The potas­si­um io­dide acts as a cat­a­lyst and speeds up this re­ac­tion.

2 H₂O₂ –> 2 H₂O + 0₂

The oxy­gen re­leased makes the dish­wash­ing liq­uid froth, form­ing a thick foam, and the food col­or­ing turns this foam dif­fer­ent col­ors.

Safe­ty pre­cau­tions

When work­ing with con­cen­trat­ed hy­dro­gen per­ox­ide, wear rub­ber gloves and pro­tec­tive glass­es, as it may cause burns if it comes into con­tact with the eyes and skin.