The Chemistry of War: Non Lethal Weapons Tear Gas

an entry by Mika Thomas, Helen Sakharova, Ko Cheng Chan

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Figure 1: A Us soldier wearing a gas mask while traveling through a field filled with tear gas during a training drill

The human body is wonderfully capable of quickly responding to its environment.  Different substances trigger different reaction in the human body.  Tear gas, or a lachrymator, is a substance that interacts violently with the mucosal membranes such as the eyes, mouth, nose and lungs.  Tear gas is actually not a gas, but a colloid, more specifically, an aerosol.  The chemical structure of tear gas is what causes it to affect us differently than other substances.

    Pepper spray also applies to the definition of a tear gas however, unlike CN gas, it is considered an inflammatory agent.  Pepper spray causes painful swelling of capillaries in the eyes and caused temporary blindness.   Pepper spray is relatively simple compared to CN and CS gases.  As the name would suggest, it is derived from peppers.  Peppers contain a group of chemicals called capsaicin.  Pepper spray is also referred to as OC spray, Oleoresin Capsicum spray.  A capsaicin is a colorless irritating phenolic amide C18H27NO3  and is responsible for giving peppers their pungent spicy flavor.  Capsaicins’ molecular structure enable them to bind directly with proteins found in the membranes of pain sensing neurons.   This causes a victim to feel an intense burning sensation, excess salivation, excess mucous production, and even vomiting.  Therefore, pepper spray should be used wisely.   The difference between sweet peppers and the infamously painful ghost pepper is the concentration of capsaicin that they both contain.

This concept of concentration also plays strongly into the potency of pepper sprays and tear gases.  Different states have different laws on the limit of capsaicin that can be used for personal protection.  Even so, for almost all pepper sprays, a 1 second blast can render a person incapacitated for fifteen minutes to an hour. Different brands of pepper spray contain different amounts of solvents such as alcohols, and water.   The more dilute the concentration of capsaicin, the less potent the spray will be.  Like other forms of tear gas, pepper spray is canned under extremely high pressures and this results in an average can of pepper spray having a shooting range of about 10 feet.  More application differences between CN gas and pepper spray can be read about here.chem chem.png

Figure 2 : an image of a molecule of capsaicin.  The black balls represent carbon atoms, the white balls represent hydrogen atoms, the blue ball represents an atom of nitrogen and the red balls represent oxygen atoms.

    Tear gas is qualified as a nonlethal weapon, but there are serious risks involved.  Tear gases qualify as a type of chemical warfare and are prohibited in war by many international warfare treaties.  However, tear gases are allowed to be used by branches of the military for training.  Tear gases are use used normally for domestic riot control or personal protection.    CN (chloroacetophenone) gas, CS (chlorobenzylidenemalononitrile)) gas and bromoacetone are the types of tear gases used by law enforcement.  A familiar form of CN gas is Mace, a popular trademark brand of CN gas sold for personal protection.

    CS gas is normally composed of a white powder mixed in a dispersal agent like methylene chloride. At standard temperature and pressure, CS forms a white crystal with a low vapour pressure and poor solubility.  CS crystals are converted into microparticulate clouds by pyrotechnic devices.  CS gas may seem to be a continuous solution or a gas, but it is also a colloid.

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Figure 3: An image of a Us soldier wearing a gas mask to avoid the painful, yet temporary effects of CS gas. CS gas appears to be a white gas, but it is composed of small particles of white solid.

    As a result, CS gas is usually stored in cans at high pressures. A can of CS contains a gas and skin irritating solvents. When this can is used, highly pressurized gas escapes a can and the gas carries ultra-fine particles of CS.  The powdered CS becomes attached to the mucous membranes of organisms. The physical effects of CS gas is felt almost immediately.  A person’s breathing rate slows and excessive use of CS gas can lead to death. The poor solubility of CS makes it that it can exist on a mucous membrane for a long period of time if not physically removed.  Luckily, wind and fresh air can removed CS particles from the skin.  Gas masks work by protecting ones mucous membranes.

    Because it has been dubbed a nonlethal weapon there is fear that authoritative forces use it too liberally.    Tear gas is technically a “less-than-lethal” weapon because it can, in some cases, lead to death.  There is controversy over allowing authoritative forces to use tear gas.  Often, law enforcers must be exposed to tear gas themselves before they gain the right to use it.  While the memory f the pain of peppery spray might stop a young officer from using it too much, an older officer might not remember the pain and use it too often.  CN gas is excruciatingly painful and is often used on protesters as shown below.  The use of tear gas has raised social controversy that has even inspired for scientific research to be conducted on tear gases.  chem riot.jpg

The Chemistry of Fusion Bombs

In the previous article, we learned about how nuclear fusion occurs naturally, specifically in stars throughout the universe. Now that we understand the very extreme set of conditions that must be present for fusion to occur, we can shift to the oppositeend of the spectrum: man-made fusion. As we have already learned, the fusion reaction gives off a great amount of energy which can be used for many practical purposes that would benefit our daily lives. Throughout the ages, it seems that it has been humanity’s goal to harness ever increasing power for its own benefit which could also destroy humanity altogether. Whether it is a bomb, or an alternative energy source in the form of a nuclear fusion reactor, those inventors who are able to achieve both are definitely making a great contribution to all mankind as long as humans are seeking peaceful cohabitation at all times.

Let’s start off with the largest nuclear fusion bomb ever detonated. The device officially designated RDS-220, known to its designers as Big Ivan, and nicknamed in the west Tsar Bomba was the largest nuclear weapon ever constructed or detonated. The nickname Tsar Bomba is areference to a famous Russian tradition for making gigantic artifacts for show. The bomb was detonatedin 1961 on Novaya Zemlya islands in Arctic Russia. This three-stage weapon was actually a 100 megaton bomb design, but the uranium fusion stage tamper of the tertiary (and possibly the secondary) stage(s) was replaced by one(s) made of lead. This reduced the yield by 50% by eliminating the fast fissioning of the uranium tamper by the fusion neutrons, and eliminated 97% of the fallout (1.5 megatons of fission, instead of about 51.5 Mt), yet still proved the full yield design. (http://www.tsarbomba.org/)

The result was the “cleanest” weapon ever tested with 97% of the energy coming from fusion reactions. The effect of this bomb at full yield on global fallout would have been tremendous. It would have increased the world’s total fission fallout since the invention of the atomic bomb by 25%. Despite the very substantial burst height of 4,000 m (13,000 ft) the vast fireball reached down to the Earth, and swelled upward to nearly the height of the release plane. The blast pressure below the burst point was 300 PSI, six times the peak pressure experienced at Hiroshima in 1945. The flash of light was so bright that it was visible at a distance of 1,000 kilometers, despite cloudy skies.

As we discussed in the first blog post, there are two types of nuclear fusion reactors that have been developed. They include the magnetic confinement reactor and the inertial confinement reactor. In the late 1940’s it seemed an irresolvable problem to scientists as how to enclose the plasma, since any contact to the reaction container wall would let the surface layer of the wall evaporate and cool the plasma rapidly, causing the fusion cease. In 1951, Lyman Spitzer had the idea to enclose the plasma in a magnetic cage. As the plasma is ionized, it consists of charged particles (positive ions and electrons) that can be influenced by a magnetic field. Their trajectory has two components: a circular motion at right angles to the magnetic field and a linear motion across the magnetic field. The Tokamak was invented by Soviet physicist Igor Tamm and Andrei Sakharov in 1952. Toroidal magnetic fields were used to avoid the particles that escaped at the poles of the magnetic field. However, a toroidal magnetic field was not able to hold the plasma in an equilibrium force balance because the field strength decreased from the inside to the outside of the toroidal field with the effect that the particles drift towards the wall. Therefore, the field lines may not take a circular course about the axis of the torus, but need to be helically looped. The scientists were enthusiastic and predicted in 1955 that in 20 years time, nuclear fusion would provide us with limitless energy. However, the magnetic confinement turned out to be much trickier than assumed. To this day, experiments and tests are being run in nuclear fusion facilities in France to prevent particles from leaving the magnetic field. (http://www.world-nuclear.org/info/Current-and-Future-Generation/Nuclear-Fusion-Power/

Now that we know that fusion is the future of clean and virtually unlimited power for all of our electrical needs, we can move forward into our next topic: Fusion in the Future, and specifically, cold fusion. Get excited to really focus on the chemistry concepts involved with this unique type of energy creation. Until then, keep reading to find out!

The Chemistry of War: Nuclear Bombs

By Helen Sakharova, Mika Thomas, and Ko Cheng Chan

In modern warfare, explosives are used all the time. They destroy bridges and barricades, stop armored vehicles in their tracks, and bury enemies in their own tunnels. But the most terrifying weapon ever invented by humans, the nuclear bomb, is on a different level entirely. Here is a weapon that can level a city with a single strike. Enough of them could even destroy the world. Yet a nuclear bomb, from a blinding explosion to a billowing mushroom cloud, is just a particularly deadly manifestation of chemistry. Lets start with the basics.

Fission

The first nuclear bombs, including the ones detonated over Hiroshima and Nagasaki, were fission bombs. They utilized uranium or plutonium, large, heavy elements that can undergo chain fission reactions. Fission is when a large nucleus falls apart into smaller nuclei, releasing neutrons and gamma rays in the process. In a chain reaction, the newly released neutrons strike the nuclei of other atoms, which then undergo fission as well, releasing even more neutrons. This cascade of fission reactions results in the huge release of energy accompanied by the explosion of an atomic bomb.

The kinetics of a chain fission reaction are particularly interesting to observe. Chain fission reactions don’t really have a “rate”, since the size of the reaction increases exponentially over time, assuming the reaction is sustained. It is necessary to note that not all of the neutrons necessarily cause further fission reactions: they may simply escape the system as a whole. They can also be captured without causing another fission reaction. If not enough neutrons cause secondary fission reactions, the number of reacting atoms decreases over time and the chain reaction sputters out. Thus, the number of fission reactions in progress, i.e. the size of the reaction, at a certain point in time can be determined by the formulae^{(k-1)t/\Lambda}. Here, Λ is the mean generation time, or the average time it takes for a newly released neuton to be “captured” by another nucleus and cause a fission reaction. As you can probably see, whether or not the chain reaction will be able to sustain itself or not depends on k, the effective neutron multiplication factor. If k is less than one, the system is subcritical, and any spontaneous or intentional fission reaction that occurs will quickly grow weaker and stop. If k is one, the system is critical, and any fission reactions will continue at a constant rate. Nuclear power plants operate at the critical point, since the constant fission reactions provide a steady source of energy. However, if k is greater than one, the system becomes supercritical. In this case, the reaction will get faster, and faster, and faster, accelerating exponentially until it spirals out of control and becomes a nuclear explosion.

This is the fission reaction of Uranium 235. Note how the chain reaction leads to exponentially more reactions taking place.

Fusion

The most powerful bomb ever detonated was the Tsar Bomba, a thermonuclear bomb that generated over 210 petajoules of energy, the equivalent of 50 million tons of TNT. Like all thermonuclear weapons, the Tsar Bomba utilized fusion. Nuclear fusion is the opposite of fission.  Nuclear fusion is the process where two light elements (elements with low atomic numbers) are fused together, forming a new nucleus and releasing a lot of energy.

At first glance, this seems illogical. How can forcing two atoms together possibly release energy? Wouldn’t the positive charges of the nuclei repel each other at close range? Indeed they do. However, at extremely close ranges, we encounter a force seldom mentioned in chemistry: the nuclear force. The nuclear force is the attractive force between two nucleons (neutrons or protons). By forcing two nuclei close enough together, this attractive force overcomes the repulsion between the protons and the nuclei join together. At this point, some of the mass is directly converted into photons, or energy. The exact amount of energy created strictly relates to the change in mass according to the equation E=Δmc2. Even though only tiny amounts of mass are lost, relatively large amounts of energy are produced.

Here is a video from CrashCourse explaining nuclear fusion.

The Hydrogen Bomb

Hydrogen bombs, or thermonuclear weapons, utilize both fission and fusion to cause the most powerful explosions ever created by humans. Inside the casing, a thermonuclear warhead of the typical Teller-Ulam design basically carries two bombs encased in polystyrene foam. The first is a fission bomb which releases large amounts of X-rays and gamma rays that are reflected off the inside of the casing back into the polystyrene foam. The irradiated polystyrene foam then becomes a plasma. This plasma compresses the second bomb, which consists of fusion fuel encased in uranium with a fissile spark plug inside. The compression from the plasma sets off a fission reaction in the spark plug, which pushes against the fusion fuel. Compressed from both sides and heated to extreme temperatures, the fuel, lithium-6 deuteride, produces tritium, which sets off a fusion reaction between the tritium and deuterium.

Step-by-step explosion of a hydrogen bomb. The arrows symbolize x-rays and gamma rays.

KNO3 the Chemistry Behind the Boom

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It comes as no big surprise that action films and explosions go hand-in-hand. As most of us have likely experienced, utter obliteration on the silver screen conveys a sense of immediate gratification that other movie-made special effects have trouble measuring up to. In this post, we embrace our inner ten- year old selves and delve into the hugely esoteric field of things going boom. It’s always nice to see the crux of a fast- paced film relate to something other than gunshots and arbitrary detonations, and 21 Jump Street puts forth a noteworthy effort to align a little sense in their big finish. We’d tell you ourselves, but Channing Tatum really said it best in this excerpt from the movie:

“Potassium Nitrate-

Don’t hate.

It’s great.

It can act as an oxidizer.

I didn’t know that,

but now I’m wiser.

It has a crystalline structure.

If you can’t respect that,

you’re a butt-muncher.

It’s a key ingredient in gunpowder.

K-No-Three!”

Tatum plays Jenko, a jock- turned- police officer who goes undercover when assigned to infiltrate a high school in his special police unit. Jenko’s course is switched with that of Schmidt, his brainy partner in crime (or justice), and subsequently is forced to suffer through an AP Chemistry course. His progressive appreciation for the subject pays off, however, when Jenko is able to utilize the knowledge he gained to blow up the limo of a drug dealer in the final chase scene with the creation of an impromptu battery bomb composed of a tequila, potassium nitrate (from shotgun shells) and lithium (from lithium batteries of a camera). Would this concoction have produced the earth-shaking explosion it did?

Lithium batteries and tequila would have produced the exothermic single displacement reaction  Li (s) + H2O (l) → LiOH (aq) +H2 (g). When lithium comes into contact with water a violent reaction occurs, resulting in the release of hydrogen gas inside the tequila bottle, since lithium is higher up in the reactivity series than hydrogen gas due to lithium’s single valence electron in its 2s1 orbital. Furthermore, alcohol is highly flammable and will combust with the hydrogen gas if there is sufficient heat. When Jenko agitated the solution by shaking the bottle, the reaction released the necessary activation energy to combust hydrogen gas and alcohol. Said combustion reaction, 2 H2(g) + O2 (g) → 2 H2O (l), has its oxygen gas provided by the oxidizing agent KNO3.

While the theoretical portion of this analysis has been relatively accurate, the tendency of hollywood to exaggerate now comes into play. Once Jenko placed the lithium inside the bottle, the reaction should have occurred almost instantly with the near immediate release of hydrogen gas, exploding before the bottle left his hands.  Instead, there is a considerable amount of lapse before Jenko throws the battery bomb. As with any reaction, the rate at which the reaction occurs depends on the required amount of activation energy. In this case, the activation energy required to produce the combustion reaction should have been generated from the exothermic reaction between lithium and water. This combined with the shaking of the bottle ultimately would result in the explosion occurring right away. Thus, although the explosion was reasonably designed, its timing was not necessarily as realistic. Moreover, the size of the explosion in the scene is inordinately exaggerated; the use of lithium would not have produced destruction anywhere near that degree. Rather, it would have been more suitable to have used an alkali metal with a more reactive potential in place of lithium to produce an explosion closer to the magnitude of the one shown on the movie screen.

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All in all, screenwriter Michael Bacall’s incorporation of chemistry into an action flick wins high points for creativity, but falls under the standard on the scale of realism. Even Bacall himself acknowledges that in hindsight, he should have “talked to an actual chemist” instead of relying on his fading knowledge back from his own AP chemistry class back in high school. Still, his enthusiasm to portray chemistry as the climatic solution to the problem in the movie is applaudable and exciting.

Chemistry of War: Stun Guns and Tasers

Continuing the topic of items used to incapacitate the enemy without killing them is with electricity rather than chemically. However, the proper functioning of a Taser is a direct result of the chemical properties of its materialistic components.  The word Taser and stun gun are used interchangeably. However, there are different types of stun guns or Tasers.  Some Tasers utilize properties of projectiles and therefore are more suited when an attacker is out of a victim’s arm reach. Taser is more often used for these types since it is actually an acronym for “Tomas A. Swift’s Electric Rifle”.

A typical Taser requires a 9 volt battery but the Tase Chemistry of War: Stun Guns and Tasers

The proper functioning of a Taser is a direct result of the chemical properties of its materialistic components.  The word Taser and stun gun are often used interchangeably.  However, there are different types of stun guns or Tasers.  Some Tasers utilize properties of projectiles and therefore are more suited when an attacker is out of a victim’s arm reach. Taser is the more commonly used word for these weapons. The word Taser is actually an acronym for “Thomas A. Swift’s Electric Rifle”.

A typical Taser requires a 9 volt battery but the Taser itself is still labeled as several 100kV. The increase in voltage is due to amplifiers and transformers in the Taser’s housing.  A battery is a cell that can convert stored chemical energy into useful energy. The amount of energy is calculated through two types of equations: reduction and oxidation. Reduction consists of an atom gaining electrons and oxidation is an atom losing electrons. Together the transfer of electrons produces a current. Tasers are able to have high voltages through the help of transformers to amplify the low 9 volts but voltages as high as 100kV.  However 100kV is not needed in most cases of authoritative force.

Common lithium battery is made up of -LiCO2(Lithium Cobalt Oxide) and LiC6

The reduction potential equations are:

Li+ +C6 +e– = LiC6      CoO2 + Li+ + e = LiCoO2

A high voltage does not determine how much damage a Taser can do.  Instead, it depends on the amount of current.

Tasers are effective in incapacitating the target by forcing their muscles to contract and release rapidly, causing twitching and convulsions. The human body is controlled by the brain through the use of electrical signals.  An electrical impulse can cause a muscle or group of muscles to contract or expand as necessary.  A Taser injects a foreign electrical impulse into the body and this debilitates a person temporarily (for as long as the Taser is being implemented). The act of a Taser’s current entering a human body is a result of the electron flow.  A Taser includes two parallel electrodes and two smaller test electrodes as shown in the diagram below.  When someone thinks about a Taser, the small test electrodes are probably what their minds first refer to.

As seen in the diagram, the battery offers a current that is amplified by the transformers found in the amplifier circuit.  Near the end of the Taser there are two parallel electrodes, a positively charged electrode and a negatively charged one.  These electrodes are made from a conductive metal plate.  Since these electrodes are placed along the curcuit, there is a high voltage difference between them.  Electrons want to flow between these electrodes, but they are placed too far apart, there is a gap in the circuit.  In comparison, the test electrodes are much closer together.  These smaller electrodes are used by the Taser wielder to see if the Taser is functioning.  If current is flowing through the Taser, then a small bluish, spark will jump between the test electrodes. The crackling spark is composed of air atoms that have been ionized by the electrical energy derived from the battery.  This noisy bright, crackling spark is an image that is normally associated with Tasers.  The parallel electrodes are two far apart to create a such a spark.  A Taser can inflict temporary damage on a person if their body is used to complete the circuit, or to fill the circuit gap between the two main electrodes.  Due to the potential difference in these electrodes, if a conductive object is placed between them, a large current flows.

 Additionally, there are flying Tasers that also use electrodes and a 9 volt batteries.  The main difference in the flying Taser is shown by the diagram below.  The electrodes fly out of the Taser as a projectile.  The electrodes are launched when the trigger is pulled.  The trigger opens a compressed gas cartridge and the electrodes are launched towards an attacker.

 The main risk in using a taser is found when it is used on someone who has heart complications.   Like any other muscle in the body, the heart contracts and expands due to electrical impulses, and a taser interferes with those interactions.  If someone has a weak heart, it is possible for them to die after being tased.  Tasers are weapons and, especially when used near water, can be lethal.  In 2010 a man in Hempstead died after being tased while wearing rain drenched clothing.

Due to the risk of Tasers, authoritative figures are required to use Tasers responsibly.  Here is an article describing how the some departments of the military are beginning to increase their use of Tasers. There is also a branch of authority called the Military Police.  Members of the Military police enforce the laws and regulations of the military.  In order to enforce such regulations members of the Military Police use nonlethal weaponry such as Tasers.  However, in order to encourage humane usage, military police officers are required to be hit with a Taser so they understand

Figure 5:  A picture of a military police officer being hit with a flying Taser gun.  This must be endured in order to earn the authority

r itself is still labeled as several 100kV. A battery is a cell that can convert stored chemical energy into useful energy. The amount of energy is calculated through two types of equations: reduction and oxidation. Reduction consists of an atom gaining electrons and oxidation is an atom losing electrons. Together the transfer of electrons produce a current. Tasers are able to have high voltages through the help of transformers to amplify the low 9 volts but voltages as high as 100kV are not needed in most cases.

Common lithium battery is made up of -LiCO2(Lithium Cobalt Oxide) and LiC6

The reduction potential equations are:

Li+ +C6 +e– = LiC6      CoO2 + Li+ + e = LiCoO2

Tasers function through two launching two prongs into the target. The farther apart the two prongs are, the more voltage is needed to complete the circuit. However a high voltage does not determine how much damage it does, instead it depends on the amount of current. Contact stun guns do not need a large voltage since the distance between the charge electrodes is fixed.

Tasers are effective in incapacitating the target by forcing their muscles to contract and release rapidly, causing twitching and convulsions. The human body is controlled by the brain through the use of electrical signals.  An electrical impulse can cause a muscle or group of muscles to contract or expand as necessary.  A Taser injects a foreign electrical impulses into the body and this debilitates a person temporarily (for as long as the Taser is being implemented). The act of a Taser’s current entering a human body is a result of the electron flow.  A Taser includes two electrodes and two smaller test electrodes as shown in the diagram below.  When someone thinks about a Taser, the small test electrodes are probably what their minds first refer to.

As seen in the diagram, the battery offers a current that is amplified by the transformers found in the amplifier circuit.  Near the end of the Taser there are two parallel electrodes a positively charged electrode and a negatively charged one.  These electrodes are made from a conductive metal plate.  Since these electrodes are placed along the surface, there is a high voltage difference between them.  Electrons want to flow between these electrodes, but they are placed too far apart, there is a gap in the circuit.  In comparison, the test electrodes are much closer together.  These smaller electrodes are used by the Taser wielder to see if the Taser is functioning.  If current is flowing through the Taser, then a small bluish, spark will jump between the test electrodes. The crackling spark is composed of air atoms that have been ionized by the electrical energy derived from the battery.  This crackling spark is an image that is normally associated with Tasers.  The parallel electrodes are two far apart to create a spark.  A Taser can inflict temporary damage on a person if their body is used to fill the circuit gap between the two main electrodes.  Due to the potential difference in these electrodes if a conductive object is placed between them, a large current flows.

Additionally, there are flying Tasers that also use electrodes and a 9 volt battery.  The main difference in the flying Taser is sown by the diagram below.  The electrodes fly out of the Taser as a projectile.  The electrodes are launched when the trigger is pulled.  The trigger opens a compressed gas cartridge and the electrodes are launched towards an attacker.

The main risk in using a stun gun is if the target already had heart problems and the shock is applied near the chest which can lead to cardiac arrest and/or death.

Here is an article of the military more recently starting to use stun guns. There is also a branch of authority called the Military Police.  Members of the Military police enforce the laws and regulations of the military.  In order to enforce such regulations members of the Military Police use nonlethal weaponry such as Tasers.  However, in order to encourage humane usage, military police officers are required to be hit with a Taser so they understand.

Conclusion: Tear Gas, Pepper Spray, and Chemical Weapons (Oh My!) 

According to reputable official the Honorable Mr. Andrew C. Weber, the Assistant Secretary of Nuclear, Chemical, and Biological Defense programs, “the Office of the Assistant Secretary of Defense for Nuclear, Chemical and Biological Defense Programs has a wide range of duties related to countering Weapons of Mass Destruction (WMD) threats.  Their team of top scientists helps us understand these threats and engage in activities and programs to counter them.  Their duties include overseeing Department of Defense science and technology investments in countermeasures that will enable the United States forces to prevent, protect against, and respond to WMD threats”. However there is still one chemical weapon that is marketed to the masses today and even used against protests: tear Gas.

 

Tear gas was first introduced World War I by the French. It was not very concentrated, and the Germans hardly noticed it was being used. In August 1914, the French fired 26 mm grenades containing ethyl bromoacetate, but the low concentration, only approximately 19cm³ per grenade, was not enough to bother the Germans. Afterwards, due to shortages of bromine, the primary chemical was switched to chloroacetone. The Germans then retaliated with a tear gas of their own making, using it for the first time in October of 1914 on the British. Again, the weapon was so dilute that the enemy combatants did not even notice.

Peaceful protesters in Tahrir Square attempt to flee from the noxious tear gas

 Since its debut in the Great War, tear gas, and its famous derivative pepper spray, has transformed from an ineffective weapon of war to a highly efficient tool for dispersing protesters. It has become a lynchpin in the arsenal of modern authoritarian regimes and has seen widespread use in recent years, with the Arab Spring and the Turkish protests being the more high-profile international cases. In an especially ironic incident, tear gas manufactured in the US, the great champion of democracy, was used on protesters in Tahrir Square attempting to enact some democratic reform. In Turkey, when Prime Minister Erdogan tried to seize historic sites and develop them for his cronies, protesters invaded Taksim Square; they were tear gassed. Luckily for them, the tear gas brought international attention to their plight, but that cannot be said of all tear gas victims.

A doctored photograph which emphasizes the inhumane actions of Lt. Pike, who had pepper sprayed a peaceful protestor.

 

Another event exemplifying the political, rather than physical, power tear gas can have was the UC Davis Occupy protest that involved Lt. Pike, a police officer who had pepper sprayed a peaceful protester for no apparent reason. The ensuing media firestorm brought new attention to the waning Occupy Movement, showing that chemical weapons aren’t always so bad. Also, the image of the cop pepper spraying the protesters birthed many amusing pictures, another positive effect of chemical weapons.

3-D Model of 2-Chlorobenzalmalononitrile (CS)

Although tear gas has numerous different forms, 2-Chlorobenzalmalononitrile (also known as CS) is the most common. CS has a chemical formula of C10H5ClN2, composed of several cyanide functional groups, Due to the hydroscopic nature of aerogels, a type of colloid, when silica aerogel is combined with CS, the fluidity, water resistance, chance of exposure and intensity of the symptoms increase.  CS gas is synthesized by the reaction of 2-chlorobenzaldehyde and malononitrile through Knoevenagel condensation. This reaction is composed of two steps: first, the nucleophilic addition of an active hydrogen compound to a carbonyl group and second, a dehydration reaction in which a molecule of water is removed. of the symptoms increase

CS-chemical-synthesis.png

ClC6H4CHO + H2C(CN)2 → ClC6H4CHC(CN)2 + H2O

There are a couple major components in tear gas. Charcoal is used as an ignitor when combined with potassium nitrate allowing the can to combust. This is because potassium nitrate gives off great quantities of oxygen when it burns, feeding the fire, while charcoal will begin to smolder when the pin is pulled. Silicon is also added so that when the exothermic reaction of potassium nitrate occurs causing super hot glass droplet to forms, igniting the other compounds. The sucrose in the can acts as a fuel source for the fire at a relatively low temperature, vaporizing the O-Chlorobenzalmalononitrile, a lachrymator, irritating the eyes or the nose. Potassium chlorate is an oxidizer creating some of the smoke, while magnesium carbonate is used to to keep the solution slightly neutral. This is all dispersed in nitrocellulose, a sticky binding, to create a homogenous mixture.

Although technically banned under the UN Convention on Chemical weapons, tear gas is not nearly as lethal as other compounds such as Ricin or Sarin gas. In fact it has to be 25 grams per cubic meter for it be lethal when only concentrations 4 grams per cubic meter are used to disperse crowds. However it is still worrying to note that chemical weapons are not just abstract concepts, created in sinister labs in shady countries, but actually used today, even here in the US.

Conclusion: Tear Gas, Pepper Spray, and Chemical Weapons

 

According to reputable official the Honorable Mr. Andrew C. Weber, the Assistant Secretary of Nuclear, Chemical, and Biological Defense programs, “the Office of the Assistant Secretary of Defense for Nuclear, Chemical and Biological Defense Programs has a wide range of duties related to countering Weapons of Mass Destruction (WMD) threats.  Their team of top scientists helps us understand these threats and engage in activities and programs to counter them.  Their duties include overseeing Department of Defense science and technology investments in countermeasures that will enable the United States forces to prevent, protect against, and respond to WMD threats”. However there is still one chemical weapon that is marketed to the masses today and even used against protests: tear Gas.

Tear gas in use

Tear gas was first introduced World War I by the French. It was not very concentrated, and the Germans hardly noticed it was being used. In August 1914, the French fired 26 mm grenades containing ethyl bromoacetate, but the low concentration, only approximately 19cm³ per grenade, was not enough to bother the Germans. Afterwards, due to shortages of bromine, the primary chemical was switched to chloroacetone. The Germans then retaliated with a tear gas of their own making, using it for the first time in October of 1914 on the British. Again, the weapon was so dilute that the enemy combatants did not even notice.

Peaceful protesters in Tahrir Square attempt to flee from the noxious tear gas

Since its debut in the Great War, tear gas, and its famous derivative pepper spray, has transformed from an ineffective weapon of war to a highly efficient tool for dispersing protesters. It has become a lynchpin in the arsenal of modern authoritarian regimes and has seen widespread use in recent years, with the Arab Spring and the Turkish protests being the more high-profile international cases. In an especially ironic incident, tear gas manufactured in the US, the great champion of democracy, was used on protesters in Tahrir Square attempting to enact some democratic reform. In Turkey, when Prime Minister Erdogan tried to seize historic sites and develop them for his cronies, protesters invaded Taksim Square; they were tear gassed. Luckily for them, the tear gas brought international attention to their plight, but that cannot be said of all tear gas victims.

A doctored photograph which emphasizes the inhumane actions of Lt. Pike, who had pepper sprayed a peaceful protester.

Another event exemplifying the political, rather than physical, power tear gas can have was the UC Davis Occupy protest that involved Lt. Pike, a police officer who had pepper sprayed a peaceful protester for no apparent reason. The ensuing media firestorm brought new attention to the waning Occupy Movement, showing that chemical weapons aren’t always so bad. Also, the image of the cop pepper spraying the protesters birthed many amusing pictures, another positive effect of chemical weapons.

3-D Model of 2-Chlorobenzalmalononitrile (CS)

Although tear gas has numerous different forms, 2-Chlorobenzalmalononitrile (also known as CS) is the most common. CS has a chemical formula of C10H5ClN2, composed of several cyanide functional groups, Due to the hydroscopic nature of aerogels, a type of colloid, when silica aerogel is combined with CS, the fluidity, water resistance, chance of exposure and intensity of the symptoms increase.  CS gas is synthesized by the reaction of 2-chlorobenzaldehyde and malononitrile through Knoevenagel condensation. This reaction is composed of two steps: first, the nucleophilic addition of an active hydrogen compound to a carbonyl group and second, a dehydration reaction in which a molecule of water is removed. of the symptoms increase

CS-chemical-synthesis.png

ClC6H4CHO + H2C(CN)2 → ClC6H4CHC(CN)2 + H2O

There are a couple major components in tear gas. Charcoal is used as an ignitor when combined with potassium nitrate allowing the can to combust. This is because potassium nitrate gives off great quantities of oxygen when it burns, feeding the fire, while charcoal will begin to smolder when the pin is pulled. Silicon is also added so that when the exothermic reaction of potassium nitrate occurs causing super hot glass droplet to forms, igniting the other compounds. The sucrose in the can acts as a fuel source for the fire at a relatively low temperature, vaporizing the O-Chlorobenzalmalononitrile, a lachrymator, irritating the eyes or the nose. Potassium chlorate is an oxidizer creating some of the smoke, while magnesium carbonate is used to to keep the solution slightly neutral. This is all dispersed in nitrocellulose, a sticky binding, to create a homogenous mixture.

Although technically banned under the UN Convention on Chemical weapons, tear gas is not nearly as lethal as other compounds such as Ricin or Sarin gas. In fact it has to be 25 grams per cubic meter for it be lethal when only concentrations 4 grams per cubic meter are used to disperse crowds. However it is still worrying to note that chemical weapons are not just abstract concepts, created in sinister labs in shady countries, but actually used today, even here in the US.