Elephant's toothpaste is a foamy substance caused by the quick decomposition of hydrogen peroxide (H2O2) using potassium iodide (KI) or yeast and warm water as a catalyst. [1] How rapidly the reaction proceeds will depend on the concentration of hydrogen peroxide. [2] [3] [4]
Because it requires only a small number of ingredients and makes a "volcano of foam", it is a popular experiment for children to perform in school or at parties.
About 50 ml of concentrated (>12%) [5] hydrogen peroxide is first mixed with liquid soap or dishwashing detergent. Then, a catalyst, often around 10 ml potassium iodide solution or catalase from baker's yeast, is added to make the hydrogen peroxide decompose very quickly. Hydrogen peroxide breaks down into oxygen and water. As a small amount of hydrogen peroxide generates a large volume of oxygen, the oxygen quickly pushes out of the container. [6] The soapy water traps the oxygen, creating bubbles, and turns into foam. [6] About 5-10 drops of food coloring could also be added before the catalyst to dramatize the effect. How rapidly the reaction occurs will depend on the concentration of hydrogen peroxide used. [7]
This experiment shows the catalyzed decomposition of hydrogen peroxide. Hydrogen peroxide (H2O2) decomposes into water and oxygen gas, which is in the form of foam, but normally the reaction is too slow to be easily perceived or measured: [2]
In normal conditions, this reaction takes place very slowly, therefore a catalyst is added to speed up the reaction, which will result in rapid formation of foam. The iodide ion from potassium iodide acts as a catalyst and speeds up the reaction while remaining chemically unchanged in the reaction process. [2] [3] [8] The iodide ion changes the mechanism by which the reaction occurs:
The reaction is exothermic; the foam produced is hot (about 75°C or 167°F).[ specify ] [2] [3] A glowing splint can be used to show that the gas produced is oxygen. [9] The rate of foam formation measured in volume per time unit has a positive correlation with the peroxide concentration (v/V%), which means that more foam will be generated per unit time when a more concentrated peroxide solution is used. [10]
1. Prepare the Mixture: In a container, mix together: ½ cup of hydrogen peroxide (30% solution), A squirt of dish soap, A few drops of food colouring (if desired).
2. Catalyst Addition: In a separate small container, mix: 1 tablespoon of potassium iodide with a small amount of warm water to help it dissolve.
3. Combine: Quickly pour the potassium iodide solution into the container with the hydrogen peroxide mixture.
4. Observe the Reaction: Almost immediately, a rapid reaction occurs: The hydrogen peroxide decomposes into water and oxygen gas (2 H₂O₂ → 2 H₂O + O₂), The reaction is sped up by the potassium iodide, which acts as a catalyst, The soap captures the released oxygen, creating a large amount of foam. The result is an impressive eruption of foam that can pour out of the container.
YouTube science entertainer Mark Rober has created a variation of the experiment, named "Devil's Toothpaste", which has a far more pronounced reaction than the version usually performed in classroom settings. [11] [12] The ingredients to create the devil's toothpaste reaction are the same as the regular elephant's toothpaste reaction, the only difference being the use of 50% H2O2 instead of the usual 35%. [13]
Hydrogen peroxide is a chemical compound with the formula H2O2. In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution in water for consumer use and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or "high-test peroxide", decomposes explosively when heated and has been used as both a monopropellant and an oxidizer in rocketry.
In chemistry, peroxides are a group of compounds with the structure R−O−O−R, where the R's represent a radical and O's are single oxygen atoms. Oxygen atoms are joined to each other and to adjacent elements through single covalent bonds, denoted by dashes or lines. The O−O group in a peroxide is often called the peroxide group, though some nomenclature discrepancies exist. This linkage is recognized as a common polyatomic ion, and exists in many molecules.
Luminol (C8H7N3O2) is a chemical that exhibits chemiluminescence, with a blue glow, when mixed with an appropriate oxidizing agent. Luminol is a white-to-pale-yellow crystalline solid that is soluble in most polar organic solvents but insoluble in water.
In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation state. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called comproportionation, also known as symproportionation.
A gas generator is a device for generating gas. A gas generator may create gas by a chemical reaction or from a solid or liquid source, when storing a pressurized gas is undesirable or impractical.
Potassium superoxide is an inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide anion. It is used as a CO2 scrubber, H2O dehumidifier, and O2 generator in rebreathers, spacecraft, submarines, and spacesuits.
Sodium peroxide is an inorganic compound with the formula Na2O2. This yellowish solid is the product of sodium ignited in excess oxygen. It is a strong base. This metal peroxide exists in several hydrates and peroxyhydrates including Na2O2·2H2O2·4H2O, Na2O2·2H2O, Na2O2·2H2O2, and Na2O2·8H2O. The octahydrate, which is simple to prepare, is white, in contrast to the anhydrous material.
Iodometry, known as iodometric titration, is a method of volumetric chemical analysis, a redox titration where the appearance or disappearance of elementary iodine indicates the end point.
In organic chemistry, organic peroxides are organic compounds containing the peroxide functional group. If the R′ is hydrogen, the compounds are called hydroperoxides, which are discussed in that article. The O−O bond of peroxides easily breaks, producing free radicals of the form RO•. Thus, organic peroxides are useful as initiators for some types of polymerization, such as the acrylic, unsaturated polyester, and vinyl ester resins used in glass-reinforced plastics. MEKP and benzoyl peroxide are commonly used for this purpose. However, the same property also means that organic peroxides can explosively combust. Organic peroxides, like their inorganic counterparts, are often powerful bleaching agents.
The iodine clock reaction is a classical chemical clock demonstration experiment to display chemical kinetics in action; it was discovered by Hans Heinrich Landolt in 1886. The iodine clock reaction exists in several variations, which each involve iodine species and redox reagents in the presence of starch. Two colourless solutions are mixed and at first there is no visible reaction. After a short time delay, the liquid suddenly turns to a shade of dark blue due to the formation of a triiodide–starch complex. In some variations, the solution will repeatedly cycle from colorless to blue and back to colorless, until the reagents are depleted.
Piranha solution, also known as piranha etch, is a mixture of sulfuric acid and hydrogen peroxide. The resulting mixture is used to clean organic residues off substrates, for example silicon wafers. Because the mixture is a strong oxidizing agent, it will decompose most organic matter, and it will also hydroxylate most surfaces, making them highly hydrophilic (water-compatible). This means the solution can also easily dissolve fabric and skin, potentially causing severe damage and chemical burns in case of inadvertent contact. It is named after the piranha fish due to its tendency to rapidly dissolve and 'consume' organic materials through vigorous chemical reactions.
The Briggs–Rauscher oscillating reaction is one of a small number of known oscillating chemical reactions. It is especially well suited for demonstration purposes because of its visually striking colour changes: the freshly prepared colourless solution slowly turns an amber colour, then suddenly changes to a very dark blue. This slowly fades to colourless and the process repeats, about ten times in the most popular formulation, before ending as a dark blue liquid smelling strongly of iodine.
Lithium peroxide is the inorganic compound with the formula Li2O2. Lithium peroxide is a white solid, and unlike most other alkali metal peroxides, it is nonhygroscopic. Because of its high oxygen:mass and oxygen:volume ratios, the solid has been used to remove CO2 from and release O2 to the atmosphere in spacecraft.
Trioxidane, also called hydrogen trioxide is an inorganic compound with the chemical formula H[O]
3H. It is one of the unstable hydrogen polyoxides. In aqueous solutions, trioxidane decomposes to form water and singlet oxygen:
The Bray–Liebhafsky reaction is a chemical clock first described by William C. Bray in 1921 and the first oscillating reaction in a stirred homogeneous solution. He investigated the role of the iodate, the anion of iodic acid, in the catalytic conversion of hydrogen peroxide to oxygen and water by the iodate. He observed that the concentration of iodine molecules oscillated periodically and that hydrogen peroxide was consumed during the reaction.
The Milas hydroxylation is an organic reaction converting an alkene to a vicinal diol, and was developed by Nicholas A. Milas in the 1930s. The cis-diol is formed by reaction of alkenes with hydrogen peroxide and either ultraviolet light or a catalytic osmium tetroxide, vanadium pentoxide, or chromium trioxide.
The Fleming–Tamao oxidation, or Tamao–Kumada–Fleming oxidation, converts a carbon–silicon bond to a carbon–oxygen bond with a peroxy acid or hydrogen peroxide. Fleming–Tamao oxidation refers to two slightly different conditions developed concurrently in the early 1980s by the Kohei Tamao and Ian Fleming research groups.
Potassium peroxochromate, potassium tetraperoxochromate(V), or simply potassium perchromate, is an inorganic compound having the chemical formula K3[Cr(O2)4]. It is a red-brown paramagnetic solid. It is the potassium salt of tetraperoxochromate(V), one of the few examples of chromium in the +5 oxidation state and one of the rare examples of a complex stabilized only by peroxide ligands. This compound is used as a source of singlet oxygen.
The anthraquinone process, also called the Riedl–Pfleiderer process, is a process for the production of hydrogen peroxide, which was developed by IG Farben in the 1940s., The industrial production of hydrogen peroxide is based on the reduction of oxygen, as in the direct synthesis from the elements. Instead of hydrogen itself, however, a 2-alkyl-anthrahydroquinone, which is generated before from the corresponding 2-alkyl-anthraquinone by catalytic hydrogenation with palladium is used. Oxygen and the organic phase react under formation of the anthraquinone and hydrogen peroxide. Among other alkyl groups (R) ethyl- and tert-butyl- are used, e.g., 2-ethylanthraquinone.
In chemistry, metal peroxides are metal-containing compounds with ionically- or covalently-bonded peroxide groups. This large family of compounds can be divided into ionic and covalent peroxide. The first class mostly contains the peroxides of the alkali and alkaline earth metals whereas the covalent peroxides are represented by such compounds as hydrogen peroxide and peroxymonosulfuric acid. In contrast to the purely ionic character of alkali metal peroxides, peroxides of transition metals have a more covalent character.
