Application of the Week (AOTW)

Polyester is a common synthetic polymer found in fabrics and water bottles. It is made through a condensation reaction involving a dicarboxylic acid and a dihydric alcohol. Polyester is widely used due to its strength and durability.

Disinfecting wipes such as Lysol use benzalkonium chloride as an active ingredient. This chemical compound is a very good antibacterial agent agent viruses and bacteria. The wipe itself is made of textiles like cotton that can easily absorb dirt and grime.

Glow sticks produce vibrant neon light when snapped because the outer tube contains an oxalate ester and a glass tube containing hydrogen peroxide. Snapping the glow stick breaks the glass tube inside, releasing the hydrogen peroxide and letting it react with the oxalate ester.

Soil in agricultural is a major contributor to global warming. This is because it consistently released nitrous oxide, or N2O, a powerful greenhouse gas, rivaling carbon dioxide in terms of global warming potential.

Algae blooms are ecological phenomena where an excess of nitrogen and phosphorus spill into the water, leading to eutrophication. These nutrients can leak into bodies of water through fertilizer in runoff, sewage, and animal waste. These blooms are dangerous because they can block the gills of fish and marine life, and block out sunlight which prevents aquatic plants from doing photosynthesis.

Cough medicine contains Dextromethorphan which is used to suppress the urge to cough by targeting the cough center in the medulla. Some side effects of this depressant drug include feelings of fatigue, nausea, and dizziness.

Rainbows are a type of optical illusion that usually appears after it rains. When light encounters water droplets, it is refracted at the boundary between water and air. As it enters the droplet, the light dispersed into the seven different colors of the rainbow.

Caramelization is a chemical reaction that occurs in cooking. When heated, sugar molecules go through a process called sucrose inversion where disaccharides are broken down into monosaccharides. They create a rich brown color and add plenty of flavor.

Fertilizer is great for plants because it contains helpful compounds like Ammonium Nitrate and is rich in valuable nutrients including nitrogen, phosphorus, and potassium.

Cigarettes and tapes contain nicotine (C10H14N2), which is a chemical compound. It affects the brain and central nervous system, practically hijacking the body’s reward system. When nicotine enters the body, it creates temporary feelings of relaxation, releasing dopamine. This feeling is very addictive.

Poison dart frogs are poisonous because of special toxins on their skin which are made up of chemical compounds known as lipophilic alkaloids. Batrachotoxin on the skin deters predators from eating these frogs because it produces a nasty, toxic taste.

Hand sanitizer contains polar molecules like alcohols which are attracted to water molecules. They create strong intermolecular bonds. Following the principle of like-dissolves-like, hand sanitizer is able to dissolve most polar bacteria.

Bronze is an alloy made up of copper and tin. Despite copper and tin being relatively soft metals which aren’t exactly ideal for making weapons or tools, combined, they form bronze which is much stronger. During the Bronze Age, it was popularly used to make sculptures, tools, and coins!

Mold is a type of fungi that grows on wet surfaces. Mold decomposed dead organic material, including wood. It is most commonly made up of hydrogen, oxygen, and carbon. Through the use of enzymes, mold breaks down organic materials by changing its chemical composition.

Aurora Borealis, or Northern Lights, appear because of the interaction of electrons with neutral atoms in the atmosphere. The main gases in the Earth’s atmosphere are nitrogen and oxygen, which give off vibrant colors during an aurora.

Ocean acidification happens when CO2 is absorbed into the water, reacting with it to form carbonic acid, or H2CO3. Carbonic acid breaks up into H+ ions and bicarbonate, HCO3-. Since there are more hydrogen ions, the pH of the ocean lowers, causing it to be more acidic.

Most seashells come from mollusks like snails, clams, and oysters to protect their bodies. Seashells are formed when these creatures extract dissolved calcium and bicarbonate from their environment. The shells are in turn made up of calcium carbonate. When the creatures who made them die, the shell remains and is used by other animals!

Acetone, C3H6O is the main constituent and a ketone in nail polish remover. It works by breaking the polymer chains of the nail polish and keeping the resulting molecules in a liquid that is easy to wipe off.

How exactly do fire extinguishers work? The agent inside is typically made up of water and potassium acetate, potassium carbonate or potassium citrate. They act as a layer of powder or foam which smothers the fire, cutting fuel from the oxygen (since fire requires oxygen to continue burning).

Fireworks undergo an exothermic redox reaction leading to an explosion. The compounds used as oxidizers are chlorates, nitrates, and perchlorates. The most common element is potassium since the color it creates won’t affect other colors from being expressed. Through oxidation, there is a lot of built up pressure that causes the firework to burst in the sky.

What’s the chemistry behind rusting? When iron is exposed to water over a long period of time, it reacts with the water and oxygen to form iron oxide, visible as rust. Both iron and steel will rust when exposed to water and oxygen. The reaction which occurs is known as oxidation.

Fuel can power a car through a chemical reaction known as combustion. Fuel contains octane, C8H18. When this is burned, the products are CO2 and H2O. This is an exothermic reaction which gives out heat. The gases push the piston within an engine which shifts gears, thereby moving the wheels of the vehicle.

Snowflakes are water molecules that form ice crystals when an extremely cold droplet of water freezes onto small debris or dust in the sky. As the crystal falls, water vapor is added to the primary body. These molecules combine in a lattice structure of hexagonal arms.

Jellyfish venom contains porin, a type of protein that makes stings very painful. Porin is composed of amino acids which create a sharp point that can break through cell membranes and release chemicals like potassium into the bloodstream. To alleviate the pain, rinse the area with vinegar or ocean water; contrary to popular belief, urine actually makes jellyfish stings hurt more.

Rubber has such a high coefficient of friction because it is made up of hydrocarbon polymer chains, chemically known as cis-1, 4 polyisoprene. Some other effects that cis-polyisoprene produce include softness and elasticity.

Our taste buds can distinguish between varying flavors because of receptor cells that can distinguish different types of ionic compounds. For example, it can tell that Na+ is salty, H+ indicates sourness, alkaloids as bitter, and sugars sweet.

Alkaline batteries function because of a specific concentration of zinc, manganese dioxide, and potassium hydroxide. Energy is derived from the reaction of zinc metal and manganese dioxide. Alkaline batteries produce the same energy as other types of batteries, but they last much longer.

Eels can’t be real creatures, right? Their shocking abilities seem like they’re straight out of a science fiction movie! Everything relates back to chemistry. The reason why eels can discharge electricity is because of special organs containing metal ions in and around their cells. When nerves join electrocytes on one side, the signal makes positive sodium ions (Na+) rush into the cell. The rush of ions creates a temporary electric current.

   3/17/24 - Penguins rejected the long wing feathers of other birds in favor of a flightless strategy. They evolved to swim gracefully underwater using flattened flippers. These feathers on these flippers are coated with a layer of wax, which is hydrophobic. This wax helps keep the penguin dry and warm by repelling the cold, icy waters.   3/10/24 - Soda is fizzy because of a chemical reaction! Citric acid reacts with bicarbonate in order to create carbon dioxide. Water in the soda dissolves the CO2 molecules, which rise and pop when the can is opened. An unopened bottle or can of soda can stay fizzy for a pretty long time in these containers because they hold a lot of pressure, which makes it easier for liquids to hold onto gas. Over time though, when most of the carbon dioxide has left, the soda will turn out flat.

Bleach can remove the color from many substances through a process called oxidation. O2 molecules break the chemical bonds within chromophores (chemicals that absorb and reflect light, thereby producing color) which causes substances to lose their color.

3/17/24 - Penguins rejected the long wing feathers of other birds in favor of a flightless strategy. They evolved to swim gracefully underwater using flattened flippers. These feathers on these flippers are coated with a layer of wax, which is hydrophobic. This wax helps keep the penguin dry and warm by repelling the cold, icy waters.

3/10/24 - Soda is fizzy because of a chemical reaction! Citric acid reacts with bicarbonate in order to create carbon dioxide. Water in the soda dissolves the CO2 molecules, which rise and pop when the can is opened. An unopened bottle or can of soda can stay fizzy for a pretty long time in these containers because they hold a lot of pressure, which makes it easier for liquids to hold onto gas. Over time though, when most of the carbon dioxide has left, the soda will turn out flat.

3/3/24 - Our body can digest food because stomach contains HCl, or Hydrochloric acid. HCl is extremely corrosive because it is made up of an abundance of H+ ions. If HCl is so dangerous, and it’s sitting in our stomachs, why won’t it hurt us? The stomach wall is protected by a thick lining of mucus and bicarbonate. Bicarbonate is very basic, thus balancing the stomach acid.

2/25/24 - At sea level, water boils at 212°F (100°C). However, on top of Mount Everest, water boils at 154°F (68°C). Why is this the case? The “Ideal Gas Law” involves the formula PV = nRT, where P represents pressure and T represents temperature. If the value of P decreases, T must decrease as a result to balance the equation.

2/18/24 - Chili peppers contain capsaicin, a chemical that makes certain foods spicy. The chemical formula for capsaicin is C18H27NO3. It bonds to TRPV1 receptors, which produce a similar sensation that makes you feel like your mouth is on fire! Some chili plants produced this chemical in order to ward off hungry herbivores, but unfortunately for these plants, it turns out that humans quite like the taste!

2/11/24 - Why shouldn’t you sprinkle salt on a snail? Snails contain a lot of water in their bodies. Salt is able to draw its water content out, causing the snail to shrivel up through a process known as osmosis. Osmosis is the phenomenon where solvents such as water are naturally drawn towards areas with a high solute concentration. If salt comes in contact with a snail’s body, water will escape and the snail will become dehydrated. 

2/4/24 - Sunscreens contain both organic and inorganic compounds. In chemical sunscreens, oxybenzone (C14H12O3) and octinoxate (C18H26O3) work to absorb ultraviolet radiation, while in physical sunscreens, either zinc oxide or titanium dioxide offer a layer of protection to reflect and spread out UV radiation. Remember to wear sunscreen on a sunny day!

1/28/24 - Milk spoils quickly because the bacteria within converts the lactose sugars into lactic acid, or C3H6O3. This byproduct lowers the pH level, making milk taste sour. Although milk goes through pasteurization before being sold in grocery stores, not all the bacteria is killed. Because milk is stored in cold environments like the fridge, the bacteria take longer to break down lactose sugars, prolonging the freshness of the milk.

1/21/2024 - Teeth are very sensitive. When a piece of food gets stuck between teeth, acids are formed that can damage tooth enamel which are made of hydroxyapatite, Ca5(PO4)3OH. Fluoride can help in preventing tooth decay because it produces fluorapatite, Ca5(PO4)3F and calcium fluoride, CaF2. Both of these compounds are more resistant to acids than tooth enamel. Many brands of toothpaste use fluoride in their products.

1/14/2024 - Popcorn kernels are made up of roughly 15% water by mass. When they are heated, the water vaporizes but the water vapor is trapped within the kernel. More heat means more built-up pressure expanding the kernel shell. Once the shell cracks, the kernel will give way and the popcorn will pop!

1/7/2024 - Oil is less dense than water, allowing it to float. Water is made up of hydrogen and oxygen atoms, while vegetable oil is commonly made of triglycerides (carbon, hydrogen, and oxygen). These triglyceride molecules are larger than molecules of water, so they take up more space, meaning that they’re less dense.

12/31/2023 - Why do onions make people cry? When onions are cut their cells release a chemical known as “syn-propanethial-S-oxide,” a rearranged form of sulfenic acids that were created when the onion was absorbing sulfur during its time in soil. This chemical vaporizes easily in the air and creates a burning sensation when it comes in contacts with the tear ducts, leading to tears.

12/24/2023 - Have you ever wondered what different “karats” of gold mean? Gold in jewelry possess different karats, which is the purity percentage of that gold. 24k gold is 100% pure gold, so 18k would be 75%, 14k is 58.3%. Anything below 24k is made up of other metals including copper and silver. Pure gold is not only expensive, but also tends to break and collect more scratches than gold combined with different alloys.

12/17/2023 - Geckos are able to stick to walls due to Van der Waal forces, which are molecular forces (not bonds!) that are attractive to other molecules. Another interesting fact is that geckos can fold their toes backwards to end the Van der Waal attraction between their feet and the surface they were sticking to. But why can’t human feet stick to walls? A gecko’s foot is layered with millions of small hairs that lets it adhere to smooth surfaces.

12/10/2023 - Coffee is notorious for keeping people awake, but how exactly does it work? Caffeine is structurally very similar to adenosine, which usually bonds to adenosine receptors in the brain. Adenosine creates the feeling of drowsiness. Ingesting caffeine causing it to block these receptors, preventing adenosine from bonding, causing someone to be wide awake.

12/3/2023 - Crude oil contains multiple different alkanes. These alkanes form a homologous series, where they can be separated by the amount of carbons they contain per molecule. These different alkanes serve different purposes, so crude oil needs to be separated by the number of carbons. This is done by fractional distillation, where, because of the increasing LDFs from the increasing carbons, there is a melting point difference. We can take advantage of the melting point difference by setting different temperatures which will boil some substances but not all of them.

11/26/2023 - Why does bread rise in the oven? Unsurprisingly, there’s a lot of chemistry behind it! Yeast and sugar are vital components in most baked goods. Yeast eats the sugar, creating ethanol and carbonic gas, otherwise known as carbon dioxide. This is known as “fermentation.” This is why bread rises in the oven, because gas is trapped in the bread!

11/19/2023 - Plastic takes forever to decompose because the materials that it is made from typically do not occur naturally in nature. Refined gases like ethane and propane are specially treated to form ethylene and propylene. The chemical bonds within plastic are difficult for bacteria to break down.

11/12/23 - We use toothpaste every day to clean our teeth (at least, I hope you do). Many popular brands of toothpaste use fluoride, which makes a tooth’s outer layer, the “enamel,” stronger. Toothpaste as a whole is generally basic, countering the acidic nature of the acids in our mouths. Hence, it’s important to brush your teeth because toothpaste prevents tooth decay!

11/5/23 - Why does huffing helium make our voices sound higher? We can produce sound due to the oscillations (vibrations) in our vocal cords. Sound travels about 344 m/s through air, but about 927 m/s through helium gas. Regular air contains nitrogen and oxygen, which are much more heavier than helium atoms. Helium atoms let our vocal cords vibrate faster, creating a sense of a higher pitch.

10/29/23 - Why do bananas turn brown? Over time, a banana will develop brown spots all over the peel. This happens because of ethylene, a naturally occurring hormone within many fruits. An unripened fruit is oftentimes more acidic than it is sugary. Ethylene allows fruit to ripen, but too much causes it to rot.

10/22/23 - Phones are able to recognize touch, letting you scroll, tap, type, and more. Many screens have a layer of indium tin oxide coated on the surface which can conduct a small amount of electricity. A small voltage is constantly being run throughout the whole screen. When your finger touches the screen, some charges are drawn near. The phone can detect which parts of the screen have lost their charge, so it is able to recognize where it’s been touched.

10/15/23 - When you bite into a pineapple, doesn’t it feel like the pineapple’s biting you back? Pineapples contain a special enzyme known as “bromelain,” which has the ability to destroy thick mucous contained in saliva. This saliva protects the lining of the mouth. Without it, the inside of your cheeks and gums are particularly vulnerable. Not only that, but since pineapple juice has an acidic pH, pineapples irritate the inside of your mouth!

10/8/23 - It may seem like the simplest thing to dry yourself off after a shower. Why doesn't the water just fall off? Because of its strong adhesive and cohesive properties.

10/01/23 - Sherbet contains chemicals that undergo an endothermic reaction when put in contact with your tongue. This gives the feeling of coolness as you roll around this tasty treat (Pearson, 2e).

9/24/23 - The Velcro on your shoes is made of hooked surfaces on one end, and smooth coils on the other end (organic chemistry). Putting those together forms a bond that can be broken with the energy exerted from your hand (Pearson, 2e).

9/17/23 - Graphite is a soft form of carbon, with weak London Dispersion Forces that allow carbon layers to slide over each other. The tip of the pencil breaks down when the graphite is put under pressure from your hand. The more pressure you put, the more darker the lines are (more graphite).

9/10/23 - Sometimes people with fillings experience a shock when biting on aluminum foil. There is a mini-electric cell occuring here: the saliva forming as a bridge, and the two metals being the positive and negative ends (Pearson, 2e).

9/3/23 - Salt is used to melt ice off roads in the winter. When salt is spread on ice, it dissolves into its component ions in the surface layer of the ice, disrupting the crystalline structure of ice and making it melt at a lower temperature, thereby making roads safer to navigate.

8/27/23 - Lewis bases are slippery. When washing your hands, the soap is leaving them, which is why they give a "scrubbing" feeling afterwards.

8/20/23 - We see things based off of the light they reflect. Light causes retinal molecules in the eye to rotate, by exciting an electron. The rotation is locked into place when the electron falls back, which gives us vision (Atkins, 7e).

8/13/23 - Zinc is often used to coat iron or steel objects in a process called galvanization, which prevents rust. Zinc is more reactive than iron, so it oxidizes first, preventing the iron from rusting.