"Black snake" is a term that can refer to at least three similar types of fireworks: the Pharaoh's snake, the sugar snake, or a popular retail composition marketed under various product names but usually known as "black snake". The "Pharaoh's snake" or "Pharaoh's serpent" is the original version of the black snake experiment. It produces a more impressive snake, but its execution depends upon mercury (II) thiocyanate, which is no longer in common use due to its toxicity. [1] For a "sugar snake", sodium bicarbonate and sugar are the commonly used chemicals. [2]
Once lit, the fireworks emit smoke and spew out ash resembling a snake via an intumescent reaction. They remain on the ground and emit no sparks, flares, projectiles, or sound.
The Pharaoh's snake is a more dramatic experiment and it requires more safety precautions than the sugar snake due to the presence of toxic mercury vapor and other mercury compounds. [1]
This reaction was discovered by Friedrich Wöhler in 1821, soon after the first synthesis of mercury thiocyanate. It was described as "winding out from itself at the same time worm-like processes, to many times its former bulk, of a very light material of the color of graphite."[ citation needed ] For some time, a firework product called "Pharaoschlangen" was available to the public in Germany but was eventually banned when the toxic properties of the product were discovered through the deaths of several children who had mistakenly consumed the resulting solid. [3]
The Pharaoh's snake experiment is conducted in the same manner as the sugar snake experiment, however, the former uses mercury(II) thiocyanate (Hg(SCN)2) instead of powdered sugar with baking soda. This must be done in a fume hood because all mercury compounds are hazardous.
After igniting the reagents, mercury(II) thiocyanate breaks down to form mercury(II) sulfide (HgS), carbon disulfide (CS2), and carbon nitride (C3N4). Graphitic carbon nitride, a pale yellow solid, is the main component of the ash. [1]
Carbon disulfide ignites into carbon dioxide (CO2) and sulfur(IV) oxide (SO2).
While carbon nitride (C3N4) will break down into nitrogen gas and dicyan
When mercury(II) sulfide (HgS) reacts with oxygen (O2), it will form gray mercury vapor and sulfur dioxide. If the reaction is performed inside a container, a gray film of mercury coating on its inner surface can be observed.
Unlike the carbon snake, which involves the reaction of sulfuric acid instead of sodium bicarbonate, the sugar snake grows relatively faster and to a significantly larger volume.
Solid fuel is used in this experiment. The solid fuel can be sand that is sufficiently covered in ethanol or hexamethylenetetramine. A white mixture of sucrose and sodium bicarbonate will eventually turn black and the snake will grow about 15–50 centimetres (5.9–19.7 in) long after it is lit. [4]
Three chemical reactions occur when the snake is lit. Sodium bicarbonate breaks down into sodium carbonate, water vapor, and carbon dioxide: [2]
Burning sucrose or ethanol (reaction with oxygen in the air) produces carbon dioxide gas and water vapor: [2]
Some of the sucrose does not burn, but merely decomposes at the high temperature, giving off elemental carbon and water vapor: [4]
The carbon in the reaction makes the snake black. The overall process is exothermic enough that the water produced in the reactions is vaporized. This steam, in addition to the carbon dioxide product, makes the snake lightweight and airy and allows it to grow to a large size from a comparably small amount of starting material. [4]
The actual formula seems to be somewhat of a secret. However, they are likely based on a nitrated pitch composition. Additionally, they are often marketed in the form of small black pellets and are nondeliquescent and shelf-stable. There are very few retailers of this product in Europe, and there is possibly only one large-scale manufacturer in the world.
Black snakes are a popular firework in India, which children play with during the festival of Diwali. Though deemed toxic by the Chest Research foundation and Pune University, black snake fireworks are still in use. The objective of the study was to determine which firework produced the most air pollution in India. The conducted study showed that the snake fireworks emitted the highest particulate matter, capable of penetrating the lungs via inhalation of smoke particles and consequently, causing significant damage. Other fireworks that emit large amounts of smoke particles include fuljhadi (Sparkler), pulpul (Firecracker), chakris (Spinning Rocket) and annar (Flowerpot Firework). [5]
In inorganic chemistry, bicarbonate is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula HCO−
3.
Carbon dioxide is a chemical compound with the chemical formula CO2. It is made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. As the source of carbon in the carbon cycle, atmospheric CO2 is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate, which causes ocean acidification as atmospheric CO2 levels increase.
A carbonate is a salt of carbonic acid, H2CO3, characterized by the presence of the carbonate ion, a polyatomic ion with the formula CO2−3. The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate groupO=C(−O−)2.
Sulfuric acid or sulphuric acid, known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula H2SO4. It is a colorless, odorless, and viscous liquid that is soluble with water.
Sodium bicarbonate (IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation (Na+) and a bicarbonate anion (HCO3−). Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite, although it is more commonly found as a component of the mineral trona.
Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the chloralkali process.
Carbon disulfide is an inorganic compound with the chemical formula CS2 and structure S=C=S. It is also considered as the anhydride of thiocarbonic acid. It is a colorless, flammable, neurotoxic liquid that is used as a building block in organic synthesis. Pure carbon disulfide has a pleasant, ether- or chloroform-like odor, but commercial samples are usually yellowish and are typically contaminated with foul-smelling impurities.
The pedosphere is the outermost layer of the Earth that is composed of soil and subject to soil formation processes. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. The pedosphere is the skin of the Earth and only develops when there is a dynamic interaction between the atmosphere, biosphere, lithosphere and the hydrosphere. The pedosphere is the foundation of terrestrial life on Earth.
Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity into two or more fragments. Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. In short, the chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction.
Calcium bicarbonate, also called calcium hydrogencarbonate, has the chemical formula Ca(HCO3)2. The term does not refer to a known solid compound; it exists only in aqueous solution containing calcium (Ca2+), bicarbonate (HCO−
3), and carbonate (CO2−
3) ions, together with dissolved carbon dioxide (CO2). The relative concentrations of these carbon-containing species depend on the pH; bicarbonate predominates within the range 6.36–10.25 in fresh 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.
Mercury(II) thiocyanate is an inorganic chemical compound, the coordination complex of Hg2+ and the thiocyanate anion. It is a white powder. It will produce a large, winding "snake" when ignited, an effect known as the Pharaoh's serpent.
Carbamino refers to an adduct generated by the addition of carbon dioxide to the free amino group of an amino acid or a protein, such as hemoglobin forming carbaminohemoglobin.
Barium chlorate, Ba(ClO3)2, is the barium salt of chloric acid. It is a white crystalline solid, and like all soluble barium compounds, irritant and toxic. It is sometimes used in pyrotechnics to produce a green color. It also finds use in the production of chloric acid.
A sodium bicarbonate rocket is a model rocket fashioned from a 35mm film canister and propelled by the pressure of a gas, often carbon dioxide, generated from the reaction of an acid with sodium bicarbonate. Sodium bicarbonate rockets are often used in science classes to demonstrate principles of chemistry and physics.
Magnesium bicarbonate or magnesium hydrogencarbonate, Mg(HCO3)2, is the bicarbonate salt of magnesium. It can be formed through the reaction of dilute solutions of carbonic acid (such as seltzer water) and magnesium hydroxide (milk of magnesia).
Carbon snake is a demonstration of the dehydration reaction of sugar by concentrated sulfuric acid. With concentrated sulfuric acid, granulated table sugar (sucrose) performs a degradation reaction which changes its form to a black solid-liquid mixture. The carbon snake experiment can sometimes be misidentified as the black snake, "sugar snake", or "burning sugar" reaction, all of which involve baking soda rather than sulfuric acid.
The dry ice color show is a demonstration of the chemical formation of carbonic acid by the dissolution of dry ice in water. The dry ice color show is usually performed in classrooms to demonstrate the properties of acids and bases, their effect on pH indicators, and the sublimation of dry ice. Setup is simple and generally involves only minor hazards, the main one being the low temperature of dry ice, which can cause frostbite upon skin contact. The carbonic acid formed in the demonstration is a weak acid and is not hazardous, being present in numerous consumer products including tonic water, soda, and beer.
The chemical redox reaction between potassium permanganate and glycerol is often used to demonstrate the powerful oxidizing property of potassium permanganate, especially in the presence of organic compounds such as glycerol. The exothermic (heat producing) reaction between potassium permanganate (KMnO4), a strong oxidizing agent, and glycerol (C3H5(OH)3), a readily oxidised organic substance, is an example of an experiment sometimes referred to as a "chemical volcano".