Chemistry Connections

Chemistry ConnectionsEpisode #14

Welcome to Chemistry Connections, my name is Paz *and my name is Olivia* and we are your hosts for episode #14 called The Chemistry Behind Ice Cream Today we will be discussing how ice cream is made and stays cold.

Segment 1: Introduction to Ice Cream

I think we’ve all heard of ice cream, the cold dessert we have on hot summer days. A multitude of flavors including mint chocolate chip, strawberry, and the classic vanilla and chocolate. The creation of ice cream in its origins have been widely disputed but it reaches as far back as the second century B.C.. Important historical figures like Alexander the Great, Nero Caesar, and King Soloman enjoyed a cold treat similar to the modern ice cream many of us eat today. Today, the total frozen dairy production is over 1.6 billion gallons making it the most popular dessert in the United States; however, few people actually know the chemistry involved in sprinkle covered and cherry topped frozen treats!

Segment 2: The Chemistry Behind Ice Cream

Topic 1 - Stabilizers

The first topic we are going to cover today is stabilizers in ice cream. Stabilizers have many purposes, but one of the main ones is to increase the mix viscosity of ice cream, which means to thicken the mixture. This increases creaminess, helps the ice cream resist melting, and limits the growth of ice and lactose crystals during storage. Stabilizers help ice cream resist melting because as the viscosity increases, the rate at which ice cream melts slows. And stabilizers help limit the growth of ice and lactose crystals through a phenomenon called diffusion kinetics. As viscosity increases, the diffusion or movement of water molecules decreases and ice crystal growth slows. So, ice cream doesn’t have those crystals in its creamy mixture. Stabilizers also prevent a water sirum mixture from leaking out of the mixture while it melts and helps prevent shrinkage during storage, so ice cream is more enjoyable. The best stabilizer has proved to be .2% sodium alginate because this increases the viscosity of ice cream the most. The formula of sodium alginate is C6H9NaO7and it is a combination of sodium (Na) and alginic acid.

Stabilizers are a type of emulsifier, which are used to connect polar and nonpolar substances. Ice cream is made of milk, which is made of water, which is polar, and made of fats and oils, which are nonpolar. Emulsifiers are particles which are polar on one end and nonpolar on the other end. In sodium alginate, the positive sodium ions make up the polar end of the emulsifier. The sodium ions experience dipole dipole intermolecular forces with the water in the ice cream. The nonpolar alginate makes up the other end of the emulsifier. The alginic acid experiences London dispersion intermolecular forces with the oils and fats in the ice cream. Once the emulsifier connects the milk of the ice cream with the oils and the fats of the ice cream through intermolecular forces, the separate ingredients combine, thickening the substance as a whole and creating a creamier ice cream that is more enjoyable.

Topic 2 - freezing point depression

Another important idea in the ice cream process for the best bite is the freezing point. The best ice creams have a lower freezing point than water which allows for a softer ice cream both for eating and getting out of the container. Instead of the fat concentration impacting freezing point, as many people think, it is the sugar concentration and its bonds with water that change the freezing point. Just for some background, hydrogen bonds between water molecules are very strong and prevent most movement of particles. At colder temperatures, the H2O molecules move slower, so the hydrogen bonds, which are a very strong intermolecular force, are even stronger. Since this makes the particles very close together, ice forms since solids are the state of matter in which particles are closest together. When a solute, in this case sugar, is added to water, it creates a solution. In this solution the sugar molecules prevent water molecules from creating hydrogen bonds and without the hydrogen bonds, ice cannot form. Therefore, the solution has to be put at such a lower temperature that the hydrogen bonds form and ice is created so ice cream is cold enough to eat. The ice cream must be at a lower temperature when it freezes, so the freezing point decreases.

Segment 3: Personal Connections

Thank you for sticking with us through all that chemistry talk! And thank you to Olivia for her wonderful explanation of sugar and hydrogen bonds in ice cream. Now, onto the fun part of the discussion.

We are interested in this topic because it is a part of our everyday lives. I don’t know about you, but I end up treating myself to some Ben & Jerry’s at least once a day. It is also important to us that we understand the chemistry behind the food that we both eat regularly. Although we only named two ways that chemistry and ice cream are related, there are actually many ways in which chemistry can define the properties that ice cream possesses. Also, these tips can help create an even better ice cream if any of our listeners would like to give it a try! Olivia, you brought in cupcakes today and cream puffs yesterday. Will ice cream be your next endeavor?

I’ll give it a try! And I’ll be sure to use a stabilizer and plenty of sugar to give you the best pint possible.

I look forward to it!

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

http://icecreamscience.com/stabilizers-ice-cream/#fn-2227-4

https://www.acs.org/content/acs/en/education/resources/highschool/chemmatters/past-issues/archive-2013-2014/ice-cream-chemistry.html

https://www.idfa.org/the-history-of-ice-cream

https://foodcrumbles.com/secret-of-ice-cream-freezing-point-depression/#:~:text=The%20freezing%20point%20depression%20in%20ice%20cream&text=Water%20is%20the%20main%20 components,interferes%20with%20the%20crystal%20formation.

Music Credits

Warm Nights by @LakeyInspired

Chemistry ConnectionsEpisode #13  

Welcome to Chemistry Connections, my name is Tejas and I am your host for episode #13 called The Chemistry of Acid Rain. Today we will be discussing the causes and effects of acid rain and the chemistry behind it. 

Segment 1: Introduction to The Chemistry of Acid Rain

If you’ve studied chemistry, and even if you haven’t, you might have heard of the term pH. A pH of 7 means the solution is neutral, a pH over 7 means a solution is basic, and a pH under 7 means that a solution is acidic. So, from the words acid rain, you might guess that it means rain that has a pH much lower than 7, and you’d be right — that’s exactly what acid rain is. But how does it form? 

Acid rain is formed when sulfur dioxide and nitric oxides (NOx for short) react with water in the atmosphere to form acids. Then, the sulfuric and nitric acids that were formed fall to the ground mixed with water in a process called wet deposition. This is what you probably think of when you hear the words acid rain, but acid rain also includes dry deposition. This is when acids don’t have the moisture to come down as rain, and instead attach to surfaces and form even larger acidic properties. Then, the next time it rains, these particles get washed into the water and travel through the ground, damaging plants and animals and potentially entering lakes or rivers. 

While acid rain is a natural phenomenon, as natural sources such as volcanoes also emit Nox and sulfur dioxide. However, most of the time, the problem is man-made. Two thirds of SO2 and one fourth of NOx in the atmosphere come from electric power generators, which burn fossil fuels to generate electricity. Cars and other vehicles also emit these gases, and so do oil refineries and other pieces of equipment used in the manufacturing industry. 

Because acid rain can harm humans and kill wildlife, it’s important to understand the chemistry behind it. Once we understand the causes of acid rain and why it occurs, we can start trying to limit the amount of sulfur dioxide and NOx we put into the air. 

Segment 2: The Chemistry Behind Acid Rain

Sulfur dioxide and nitric oxides are produced by the combustion of fossil fuels. When these gases rise up into the atmosphere, they can react in a few different ways to produce acids. 

Two molecules of sulphur dioxide can react with diatomic oxygen gas to produce two molecules of sulfur trioxide. Then, each of those sulfur trioxide molecules reacts with liquid water from cloud droplets to produce H2SO4, or sulphuric acid. This is the acid that then falls to the ground with water as acid rain.

Alternatively, 2 molecules of nitrogen monoxide can react with diatomic oxygen gas to produce two molecules of nitrogen dioxide. Then, those two molecules react with water to produce nitric acid, HNO3, and nitrous acid, HNO2. 

So we have these three end products, H2SO4, HNO3, and HNO2. What makes these acids? According to the Bronsted-Lowry theory, any compound that can transfer a proton, or an H+ ion, to another compound is an acid. As you can see from the makeup of these products, they all have hydrogen atoms ready to be given away. However, two of these products are more important than the other. These are nitric acid and sulfuric acid. Both of these are strong acids; this means they are more stable when they have donated an H+ ion. Strong acids dissociate fully to completion, so when nitric acid and sulfuric acid dissolve in water, they donate an H+ ion to H20 to form large amounts of H30+. This is important because H30+ is what makes things acidic; therefore, when nitric acid and sulfuric acid dissolve in water, they produce highly acidic solutions. This is what makes up acid rain and makes it dangerous. 

Now that we’ve talked about how acid rain forms and why the emission of sulfur dioxide and NOx produce highly acidic solutions, we should talk about how this acidity is measured. This goes back to the beginning of our podcast when I mentioned pH — a pH of 7 is neutral, over 7 is basic, and under 7 is acidic. But what exactly is pH? Well, a pH is an easy way to understand exactly how much H30+ is in a solution. To find pH, you take the negative log of the concentration of hydronium in the solution. The higher the concentration of H3O+, the more acidic the solution and the lower the pH. As we just learned, acid rain is formed when the strong acids nitric acid and sulfuric acid dissolve in water. This means that acid rain has a very low pH. More specifically, any precipitation with a pH lower than 5.6 is classified as acid rain. 

Segment 3: Personal Connections

So why is this important, and why did I choose to do a podcast about this? What made acid rain interesting to me is that most people have heard of acid rain, but they don’t really know what it is or how it works. When the topic of pollution and saving the environment is brought up, you hear a lot about how the burning of fossil fuels traps carbon dioxide in the atmosphere, but not as much about the emission of sulfur dioxide and NOx. Hopefully after listening to this podcast, you understand the relationship between fossil fuels and acid rain — it's yet another reason why we have to switch to clean energy if we want to save our planet.

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

https://en.wikipedia.org/wiki/Acid_rain

https://www.epa.gov/acidrain/what-acid-rain#:~:text=Acid%20rain%20results%20when%20sulfur,before%20falling%20to%20the%20ground. 

https://letstalkscience.ca/educational-resources/stem-in-context/what-acid-rain 

Music Credits

Warm Nights by @LakeyInspired 

Chemistry ConnectionsEpisode #12

Welcome to Chemistry Connections, my name is Jiya Pandit and my name is Olivia Kim and we are your hosts for episode #12 called the chemistry of art restoration and conservation. Today we will be discussing how many art pieces have been fixed and preserved through the application of chemistry concepts.

Segment 1: Introduction to Chemistry of maintaining and fixing art pieces

When you enter an art museum, you may forget the many efforts of artists, conservators, and even scientists behind the impressive masterpieces. Just as the paintings are something to marvel at, the meticulous process behind restoring and preserving the art works is just as fascinating. While the process of fixing art may appear to just consist of applying new layers, laboratory methods - some of which we have explored and learned about in AP Chemistry - are employed to ensure the best materials and techniques are being used to repair the artwork.

Although the techniques used to restore and conserve art can be very similar, there is a key difference between art restoration and conservation. Art restoration refers to the process of fixing an object so that it returns to its original condition or appearance, while art conservation refers to the process of preserving an artwork with the intent of preventing any further deterioration or discoloration. Art conservation was first introduced during World War 2 due to the findings of undamaged works from Michelangelo and Vermeer. This was one of the first leading causes for conservation practices after the war. A famous example of art restoration is of the Sistine Chapel frescoes throughout the 1980s-1990s. However, not all art restorations or art conservation efforts are successful, which is why chemistry and other scientific disciplines have had a greater presence in the field of art.

Segment 2: The Chemistry Behind Art Restoration and conservation.

Now that we’ve discussed the historical aspect of art restoration and conservation, let’s delve deeper into how it’s connected to chemistry. I will be covering art restoration, and later, Jiya will take over with art conservation!

Topic 1: Art restoration

The first part of fixing and maintaining art is the process of art restoration. Certain art restoration processes involve methods we’ve learned about this year, but it really depends on the material used to create the art (you’re going to hear me say this a lot!).

A crucial part of art restoration is making sure that the methods employed to fix the respective art piece are with the techniques and mediums used by the original artist. Especially in very old artworks, where the materials are not commonly used or easy to access today, applying scientific methods to art is necessary. To better understand the process, I will be talking about a specific art restoration case. In the restoration of “The Plague in Lucca'' (a painting done by Italian artist Lorenzo Viani), such methods were used. For some more context, Viani’s painting had undergone a restoration process post-WWII, however that was not very effective. Recently, the artwork has undergone another restoration, this time with a more scientific and successful approach.  

The restoration of Viani’s painting, as with many other artworks, was a two step process. The first part of the process - which relies heavily on non-invasive techniques - allows scientists and artists to look at the details of the painting, such as the different paint layers and the original colors of the artwork. Images of the painting were taken at different wavelengths, which relates to concepts of electromagnetic radiation we briefly covered this year in AP Chemistry. Since each element produces a different atomic spectrum and emits a unique light when electrons transition between energy levels, the multiband imaging method helped scientists determine what elements are found in the pigments of the painting. For example, in Viani’s artwork, samples of lead, zinc, mercury, chromium, barium, and iron were detected in the pigments. This technique also helps scientists identify the exact colors used by Viani, which is very helpful for art conservators. In combination with the emission spectrum, X-ray fluorescence (XRF) analysis is also used to determine what elements make up certain pigments in the painting. XRF can identify the chemical makeup of the pigments by measuring the fluorescent X-ray emitted by a sample when the samples becomes exposed to an X-ray source. Since each element produces a unique fluorescent X-ray (similar to multiband imaging), data from XRF can provide specific information about the pigments. For instance, data from XRF indicates that a mixture of vermillion (HgS - mercury (ii) sulfide) and chrome green (Cr2O3 - chromium (iii) oxide) pigments could have been used by Viani. 

The second part of the process involves destructive methods, including a combination of mass spectrometry, Raman analysis, and gas chromatography. Destructive methods give more insight about the exact nature of the chemical, since non-invasive techniques can only reveal so much. Very small samples of the artwork underwent the process of mass spectrometry and gas chromatography, and the results of these two methods provided valuable information about what oils were used to bind the pigments. Mass spectrometry is the process of injecting atoms from the sample into the mass spectrometer instrument, which produces a mass spectrum. The mass spectrometer uses deflection to determine an object’s mass, and this can be used to identify the specific elements in the sample. Knowing the chemical makeup of the oils that hold the pigments together is crucial to the art restoration process because art restorers want to fix the painting using mediums that are very similar if not identical to the materials used when the artwork was first created.

Even though I’ve focused on the chemistry of one specific art restoration case, the techniques used to restore Viani’s painting are fairly consistent with other cases. As I’ve said before, the laboratory techniques are very dependent on the age and materials of the artwork, but there is a general two step analytical process when deciding the best way to mend the painting.

Topic 2: Art conservation

The second part of preserving art is art conservation, which is the process of preserving art pieces whether it be architecture or even statues from future damages.  

A big part of conserving art requires a lot of in-depth research and analysis of either a painting or sculpture to receive accurate data regarding what procedure should be used to fix the art piece so that there isn’t much damage in the future. This is where the AP Chemistry topics, mass spectrometry and gas chromatography (known as GC/MS) come into play. These specific techniques allow biologists to identify the compounds within the art piece by taking a tiny piece of the art and placing it into a GC/MS machine, which can then help pinpoint what treatment should be used to conserve the art. The GC/MS machine can also determine the reasoning behind discoloration or cracks on a piece. 

For example, there was a mission for conserving Buddha statues of Bamiyan, which represent Buddhist Art. During the war in Afghanistan in 2001, the statues began to get popular and well known, causing the Taliban to destroy the statues. Through the following years, organizations began to conserve the destroyed statues using techniques such as GC/MS leading to the findings of the organic paint binders and a deeper understanding of cultures in Asia. Through AP Chemistry topics such as extractions, desalting, and hydrolysis, substances such as egg proteins in this specific conservation, from the samples can be determined via the GC/MS. 

So what’s the science behind this? The full procedure of the GC/MS occurs in multiple steps. The 1st step, like in art restoration, is analyzing the art. One way this can be done is through nano-indentation microscopy, allowing scientists to analyze small parts of a piece to figure out if there is degradation or oxidation by applying a force onto a small piece of the art. Once analyzing has finished, the 2nd step begins. Gas chromatography is the process of separating substances in a compound. Through the use of injecting the sample into a mobile phase, with the help of an inert gas, it picks up the substances to get tested. The other phase is the stationary phase, which is when the mobile phase passes through a column. The data gathered from the chromatography is transferred to a chromatogram, a graph that shows the different components in the sample, each represented by a peak. Adsorption, an AP Chemistry concept, also occurs during gas chromatography. Adsorption occurs during the stationary phase in the column causing the substance to separate. This leads to the mass spectrometry section where the spectrometry analyzes each gas, specifically the masses of each of the substances by deflection like Olivia said. Thus helping determine the actual substances in the art piece by comparing the masses to other known masses. 

Along with what I previously stated, although GC/MS can be very helpful in determining materials in the art piece, a particular aspect that scientists are still trying to figure out when trying to conserve art pieces, is whether or not the treatment going to be used is safe, that it won’t cause future damages, or that they wouldn't lose the original piece. However, removing surface dirt, varnish, retouching areas, and fixing dents, can have a big impact on small pieces that need conserving. 

Segment 3: Personal Connections

Olivia: You may be wondering why we chose this specific topic. The reason I chose the topic of art conservation and restoration is because I really enjoy making art in my free time, and I’m interested in potentially studying art history in college! Whatever I end up doing, I want to keep art a part of my life, so learning about how STEM related subjects - like chemistry - are directly related to artistic fields is really fascinating!  

Jiya: The reason that I chose art conservation and restoration as the topic is because I also have an interest in art, and although I'm not a great artist, it's entertaining and fun to do on the side! I don’t particularly want to do anything in the future related to art, but I know I want to keep art in my life whether it be drawing or painting and incorporating chemistry into art, two things that I enjoy, are really interesting to learn about and to see how chemistry is in even the smallest of things!

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. See you next time!

Sources:

• https://heritagesciencejournal.springeropen.com/articles/10.1186/s40494-015-0055-0 
• https://blogs.getty.edu/iris/conservation-tools-the-gc-ms-instrument/
• https://www.chemistryworld.com/features/the-art-of-conservation/3009092.article
• https://en.wikipedia.org/wiki/Mass_spectrometry 
• https://en.wikipedia.org/wiki/Gas_chromatography 
• https://www.brhoward.com/new-blog/2018/8/28/whats-the-difference-between-conservation-and-restoration 
• https://www.thermofisher.com/blog/ask-a-scientist/what-is-xrf-x-ray-fluorescence-and-how-does-it-work/ 
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5381772/ 
• https://asiarta.org/introduction-to-conservation/oil-paintings/painting-conservation-techniques/ 
• https://www.nature.com/articles/s41598-020-64892-7

Music Credits

Warm Nights by @LakeyInspired

Chemistry ConnectionsEpisode #11 

Welcome to Chemistry Connections, my name is Lilly Wurtz and my name is Annie Stocks Natalias and we are your hosts for episode #11 called The Chemistry Behind Diamonds. Today we will be discussing the structure of diamonds as well as the main method used to create artificial diamonds: the high pressure, high temperature method.

Segment 1: Introduction to DIAMOND STRUCTURE

• Diamonds are made of elemental carbon and are allotropes of carbon. Allotropes are the same element but with different structures and arrangements in space.
• Diamonds form covalent network solids. Each carbon atom is covalently bonded to 4 other carbon atoms with covalent bonds. Covalent bonds involve the sharing of electrons so that the valence shell is satisfied. A repeating pattern forms a 3D network of atoms.
• “Real” diamonds (made naturally) were formed billions of years ago deep in the earth’s mantle and were brought to the surface most likely by a volcanic eruption. They take very long to form, making them essentially nonrenewable. 
• Synthetic (or lab grown) diamonds can grow in just one week in a lab. These diamonds are not often used for jewelry but rather used industrially. 

Segment 2: The Chemistry Behind CREATING SYNTHETIC DIAMONDS

• There are many methods used to create diamonds. This includes high pressure, high temperature, chemical vapor deposition, detonation of explosives, and ultrasound cavitation.
• These methods use something called diamondoids, which are very small pieces of diamond.
• In the High Pressure, High Temperature method, the large amount of pressure needed is supplied by the “press”. 
• In the high pressure, high temperature method, diamond seeds are placed at the bottom of a press. The press is heated above 1400 °C which melts a solvent metal. The metal then causes the high purity carbon source to dissolve. This solution is transferred to the small diamond seeds and the precipitate grows the diamondoid into a large, synthetic diamond.
• The reason you are able to dissolve the carbon into the metal is because of the strength of the various intermolecular forces. Adding heat and pressure, adds so much energy that the intermolecular forces are overcome. This causes the particles to separate because the forces holding them together are weakened. These weakened forces in both the carbon and the metal allow the solution to form. 
• The solute-solvent attractions are stronger than both the solute-solute attractions and the solvent-solvent attractions. This creates an alloy, which is normally a metal dissolved into another metal but it can also be created with carbon dissolved into a metal. This solution becomes supersaturated, meaning that the metal can’t hold any more carbon. The carbon then precipitates in the form of a crystal, growing the diamondoid. 

Segment 3: Personal Connections

• You can condense a sometimes multi billion year process into less than a week. 
• Many of the diamonds found in the past and those used today can be dated back to the formation of the earth and being able to recreate something formed by such a profound event as the creation of the planet in a simple lab is amazing. 
• Even though they have not been widely adopted by jewelers, they look identical to the naked eye. This is because they are chemically identical and are diamonds. This is why using the words “real” and “fake” aren’t accurate. They are both real, one is just lab grown. Because synthetic diamonds are, in fact, “real” diamonds, they will last forever, which is the main allure of diamonds in the first place.
• Diamonds aren’t a complicated compound but rather the form of a single element. Imagine the fact that graphite and diamonds are the same thing just in different forms.
• They are incredibly important in industrial settings as well as because of their use in engagement rings and jewelry.

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

https://www.forbes.com/sites/meriameberboucha/2018/08/22/this-is-how-synthetic-diamonds-grow/?sh=29d7204869d7

https://en.wikipedia.org/wiki/Synthetic_diamond

https://www.azom.com/article.aspx?ArticleID=8494

https://www.impressjewelers.com/blog/how-are-diamonds-made-and-what-are-diamonds-made

https://www.scientificamerican.com/article/how-can-graphite-and-diam/#:~:text=In%20a%20diamond%2C%20the%20carbon,an%20infinite%20network%20of%20atoms.&text=Moreover%2C%20diamonds%20disperse%20light.

https://www.diamonds.pro/education/how-diamonds-are-formed/

Music Credits

Warm Nights by @LakeyInspired

Chemistry ConnectionsEpisode #10  

Welcome to Chemistry Connections, my name is Finnian Mayer and I am your host for episode #10 called Building a better burger. today I will be discussing how chemistry can be used to create the best possible burger. 

Segment 1: Introduction to Burgers

• One of the quintessential fast food items, the burger has transcended its humble origins to become an absolute staple in the food scene, being served everywhere from McDonalds to Michelin starred restaurants. And while almost every burger shares a similar base of characteristics, having a top and bottom bun with a beef, chicken, or vegetable based patty in the middle, burgers are the ultimate customizable food, with choices that can be made on every inch of the burger, creating a unique experience tailored to an individual's tastes and preferences. While I will certainly not claim to make the best burger in the world, nor even the best burger I have ever had, I have come up with a recipe which I believe that I, and hopefully others, will thoroughly enjoy. I have always been a fan of spicy food, so my burger will have homemade mayonnaise flavored with calabrian chillies ( a pickled italian chili) and black pepper. To balance the spiciness and richness of the mayo, I will also add a tangy slaw to the top of the burger. The burger itself will be made of dry-aged ground brisket, while the bun will be a toasted brioche roll. 

Segment 2: The Chemistry Behind Burgers

• Mayo: 
• In order to get the best and most flavorful Mayonnaise, it is best to make your own. And, although it might initially seem like a difficult food to create, it is really only two ingredients which come together in a simple emulsion. 
• An emulsion occurs when two normally immiscible substances, such as oil and egg yolk, see a reduction in their surface tension allowing the substances to mix. 
• In cooking, emulsions require agitation, such as why oil and vinegar dressing must be shaken to mix it into a homogeneous substance. 
• For mayonnaise, the oil must be added drop by drop to the egg yolk so as to slowly decrease the egg yolk’s surface tension and gradually begin the emulsion. After every drop, vigorous whisking is needed. Once the emulsion begins, the oil can be added much more quickly. 
• Slaw: 
• Another key aspect of a burger is the slaw which tops the burger itself, made up predominantly of acid (rice wine vinegar and lemon juice) and vegetales (cabbage and radishes) and fruit (pineapple). 
• Even though it wouldn’t really be possible in the first place, a burger topped with only acid would be too strong and ruin the taste of the burger. 
• Topping a burger with raw cabbage would also not achieve a desirable effect, as it would be too plain and alkaline, having no taste to enhance the burger. 
• Cabbage has the added property of serving as an acid-base indicator when it is juiced, turning red when an H3O+ is attached and yellow when an OH- is attached. This is due to red and purple cabbage having an Anthocyanin molecule.
• Beef: 
• Dry Aging 
• One of the ways to enhance the burger itself is by dry-aging the meat before grinding it. 
• For our burgers, we will use brisket as it is natural around an 80% protein 20% fat ratio, which is perfect for a rich, smash style burger that we are going for. 
• Brisket is normally around 75% water when it is first butchered, and while water is an important part of beef, too much water results in a weaker Maillard reaction and less flavor. 
• To combat this hurdle, we will dry age the brisket before grinding it. Dry aging is the slow process of hanging beef or leaving it on a rack for weeks in order to reduce the water content of it through slow evaporation. As the beef’s temperature slowly rises in the temperature controlled dry aging room, water evaporates off of the surface of the beef. 
• Cooking: Maillard reaction
• The Maillard reaction is the browning on the surface of the meat that gives beef its appealing flavor. 
• This reaction only occurs at high heat, indicating a high activation energy needed (boiled beef is gray as no maillard reaction occurs) 
• In order to get the best maillard reaction with the most caramelization of the beef, I will use a cast iron pan as those hold heat extremely well and can be used on the top of a charcoal grill, which is able to get much hotter than a conventional gas burning or electric stove. 
• Cast iron is made from iron, which is an amazing electrical conductor due to the metallic bonding that occurs with the metal cation and a sea of electrons. The electrons in the sea move, thus creating the moving charged particles required for electrical conductivity. 
• Bun: 
• Toasted brioche bun is my choice for this burger. 
• By toasting the bun, the outer layer of the bread undergoes a combustion reaction which is a chemical change. The combustion reaction is indicated by the smoke that arises from the toaster or pan in which the bread is toasted. 
• This is also an endothermic reaction as the bread takes heat from the pan (its surroundings) and thus feels warm. 

Segment 3: Personal Connections

I have always been interested in cooking and love to try and replicate meals that I have eaten out at home. Burgers are one of my favorite foods and I have been fortunate enough to try burgers from around the country and even in a few foreign countries. Along this burger journey, I have had some incredible burgers with delicious elements, such as an amazing topping or especially flavorful beef. That said, almost none of the burgers I’ve had have gotten everything right, from the bun all the way to the toppings and patty. My goal was to use chemistry and some of my personal taste to create a burger which hit on all of the flavors I wanted it to while being prepared in the optimal way to get the most out of each and every ingredient. 

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

https://www.provisioneronline.com/articles/106468-impact-of-two-chamber-rh-on-water-loss-in-dry-aged-beef#:~:text=One%20of%20the%20main%20changes,the%20meat%20from%20spoilage%20microorganisms.&text=This%20plastic%20bag%20application%20reduces,thus%20increasing%20saleable%20meat%20yield.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4872334/#:~:text=Meat%20flavor-,The%20key%20effect%20of%20dry%20aging%20is%20the%20concentration%20of,%E2%80%9Cdry%2Daged%20beef%E2%80%9D.&text=earthy%20flavor%20profile.-,During%20the%20dry%20aging%20process%2C%20the%20juices%20are%20absorbed%20into,4%2C%206%2C%2021%5D.

https://www.netmeds.com/health-library/post/alkaline-diet-5-incredible-alkaline-rich-foods-that-promotes-overall-health#:~:text=Green%20leafy%20veggies%20are%20said,and%20build%20a%20robust%20immunity.

https://www.seriouseats.com/what-is-maillard-reaction-cooking-science

Music Credits

Warm Nights by @LakeyInspired 

Chemistry ConnectionsEpisode #9  

Welcome to Chemistry Connections, my name is Scott Hunt and I am your host for episode #9 called Blue light Today I/we will be discussing how blue light affects your eyes.

Segment 1: Introduction to Blue light

Introduce the episode topic

Include definitions, vocabulary, interesting background information and context

Light is an electromagnetic radiation that travels in waves and is a form of energy. The different colors of light is due to differences in wavelength and frequency of the waves. A short wavelength will have a higher frequency which will result in more energy. For example ultraviolet rays is another type of electromagnetic radiation that has a smaller wavelength than visible light and therefore more energy per photon. 

Retina.- a light sensitive tissue that when light hits it, the retina sends signals.

Cornea- a transparent on the outside of the eye

Pupil- the black part of your eye

Iris- the colored part of the eye

Lens- right behind the iris and pupil

Photoreceptor cells- cells in the retina. 

The cells need molecules called retinal to sense light and trigger the signals that get sent to the brain

Excitation is when photons and the energy from photons is absorbed by a molecule. The molecule is then in an excited state, which is when an electron moves into a higher energy level. A result of excitation can be a reaction

Segment 2: The Chemistry Behind Blue light 

Have a natural transition into an example… no need to say “segment 2”

Provide detailed explanations of the chemistry that is related to your topic.

Remember that you must have a minimum of 2 topics from ap chem that you can explain here as related to your episode

There is natural and artificial. Natural is the wavelengths that bounce off the air molecules and cause the sky to be blue. Artificial l blue light is the light from our phones and technology. Blue light might appear to look white or other colors. Blue light has one of the shortest wavelengths (400 to 450 nanometers) and highest energy. The short wavelengths are not able to be blocked or reflected by the eye’s cornea and lens. This allows the blue light to have direct contact with the retina. 

Blue light exposure causes the retinal molecules to go through excitation. The energy from blue light photons is absorbed by retinal molecules which react to form non degradable material known as lipofuscins which is toxic as well as retinal condensation products.

Segment 3: Personal Connections

What interested you in this topic? Why is it important? Anything else you’d like to share.

I am interested in this topic because I use the computer often playing games and doing school work as well as using my phone in my free time. It is important because computers and phones are the future and something everyone uses in their daily lives.

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

List your sources here. Make sure they are linked. Wikipedia cannot count for more than 50% of your sources.

https://phys.org/news/2018-08-chemists-blue.html#:~:text=Karunarathne's%20lab%20found%20that%20blue,D.

https://blutechlenses.com/blog/what-is-blue-light/#:~:text=Blue%20light%20is%20a%20color,produces%20higher%20amounts%20of%20energy.

https://www.nei.nih.gov/learn-about-eye-health/healthy-vision/how-eyes-work#:~:text=When%20light%20hits%20the%20retina,into%20the%20images%20you%20see.

https://www.health.harvard.edu/blog/will-blue-light-from-electronic-devices-increase-my-risk-of-macular-degeneration-and-blindness-2019040816365

https://www.nature.com/articles/s41598-018-28254-8

https://en.wikipedia.org/wiki/Excited_state

Music Credits

Warm Nights by @LakeyInspired 

Chemistry ConnectionsEpisode #8  

Welcome to Chemistry Connections, my name is Barron Brothers , my name is James Huang and we are your hosts for episode #8, The Chemistry of Acid Rain. Today we will be discussing why acid rain is so harmful and its effects on the city and the ecosystem.

Segment 1: Introduction to Acid Rain

As the world population continues to increase, the resources required to maintain this population also increase, including factories to make products for the consumer, cars for transportation, and food. However, many do not consider the environmental implications just by living in today’s world as our environmental situation continues to decline. One of these effects is the increase of acid rain due to the amount of pollutants released by industrial processes and traditional power plants.

Acid rain is rain mixed with pollutants that lower the pH of the rain. A weak acid is an acid that dissociates little in water, versus a strong acid that dissociates almost completely. Ka values measure how much an acid dissociates in water. For weak acids, Ka<1, and Ka>1 for strong acids. A buffer is a solution made up of a weak acid and its conjugate base that resists changes in pH.

Segment 2: The Chemistry Behind Acid Rain

Non-polluted rainwater is slightly acidic (pH=5.6) because the evaporated water reacts naturally with the carbon dioxide in the air, forming carbonic acid. Carbonic acid then dissolves into hydronium ions (H3O+) and its conjugate base (the negative ion dissolved in the solution - in this case, HCO3-). In the case of carbonic acid, there is still a hydrogen atom available in the conjugate base of what we call mechanism 1. With this, HCO3- reacts with water again in the second mechanism. Here are some reactions to show you what we mean:

Pollutants from factories and car emissions contain gaseous sulfates and nitrates, which react with the evaporated water as well in reactions similar to carbonic acid.

Comparing the Ka values of the acids, we can see the effects of each additional pollutant on the acidity of the acid rain. As the Ka value increases, the amount of dissolved acid particles increases, lowering the pH of the rain more.

The Ka values of HNO3 and H2SO4 are relatively high compared to relatively low ones, such as H2CO3. Since CO2 is present naturally in the air, this explains why rainwater is slightly acidic. However, nitrates and sulfates are a result of unnatural pollution, such as from factories and fertilizers. Because of these Ka values, H2SO4 and HNO3 reduce the pH even further and have a greater effect than H2CO3, as the pH of acid rain ranges from 4.2 to 4.4. Also, the pH scale is logarithmic, meaning that the difference in acidity between water (pH=7) and rainwater is much lower than that of rainwater to acid rain, even if the pH difference is smaller. In addition, car and factory pollution forms additional CO2, forming more H2CO3 and decreasing the pH of acid rain further.

Acidic rain also reacts with building materials, such as limestone, aluminum, and steel, causing corrosion. Limestone (CaCO3) reacts with sulfuric acid to produce calcium sulfate (CaSO4), carbon dioxide, and water.

Therefore, the sulfuric acid in acid rain strips away at the calcium carbonate, leading to faster weathering compared to normal rain. This is very problematic, as limestone is used in both cement and concrete, so acid rain will have a severe effect on most buildings and structures around the world. In aluminum and steel, a similar process occurs, as various acids react with the metal to produce an aqueous solution, corroding the metal on certain buildings. Since steel is made up mostly of iron (97%), the iron is an appropriate representation of the decay of steel. For sulfuric acid, here are some reactions depicting the process:

Since many skyscrapers are made up of steel, this is a problem particularly in cities. Another effect of acid rain is how it takes away nutrients from the soil. The hydronium ions pull out vital nutrients from the clay, such as magnesium ions, and replace them with hydronium ones.

When the H3O+ in acid rain flows from the clay and mixes with lakes and other bodies of water, the pH of the water will drop. Most ecosystems are very sensitive to pH drops; i.e., most fish eggs will not hatch if pHwater<5. 

Resisting acid rain

Soils with calcium carbonate act as a buffer against acid rain. There are many ways to resist the effects of acid rain, one of which being the soil itself. Soil contains calcium carbonate (CaCO3), which can react with sulfuric acid to produce the weaker carbonic acid, as shown below. 

Calcium carbonate can also be used to reduce acid rain at its source. In factories where sulfur dioxide is produced, calcium carbonate can be injected into smokestacks, reacting with the sulfur dioxide to produce pH-neutral calcium sulfate (CaSO4). Carbon dioxide is still produced, but, using the same concept as the soil, the Ka of carbonic acid is lower than that of sulfuric acid. Therefore, this would lessen the factory’s impact on the pH of the rain, as a smaller Ka value has less impact on the environment.

Segment 3: Personal Connections

The issue of acid rain is paramount because today’s society is ignoring global warming and continuing to pollute. If excessive pollution continues, acid rain will become more common. This will cause more damage to ecosystems and buildings and endanger the safety and quality of life for many across the globe. We as the younger generation will grow up in this world, so we must pioneer the changes needed, such as regulating factory pollution, basing the economy on electric transportation rather than oil, and creating more green space free from chemical pollution. This is the only way to improve this world for us and all future generations.

Thank you for listening to this episode of Chemistry Connections. For more student-run podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

• https://www.epa.gov/acidrain/what-acid-rain#:~:text=Acid%20rain%20results%20when%20sulfur,before%20falling%20to%20the%20ground
• http://chemistry.elmhurst.edu/vchembook/196soil.html#:~:text=The%20sulfuric%20acid%20reacts%20with%20the%20limestone%20in%20a%20neutralization%20reaction.&text=The%20calcium%20sulfate%20is%20soluble,the%20limestone%20dissolves%20and%20crumbles. 
• https://www.epa.gov/acidrain/effects-acid-rain#ecosystems
• https://en.wikipedia.org/wiki/Acid_rain 
• https://www.webelements.com/iron/chemistry.html#:~:text=Reaction%20of%20iron%20with%20acids,2)6%5D2%2B.&text=If%20oxygen%20is%20present%2C%20some,oxidizes%20to%20Fe(III).

Music Credits

Warm Nights by @LakeyInspired

Chemistry ConnectionsEpisode #7

Welcome to Chemistry Connections, my name is Victoria Villagran and I am your host for episode #7 called The Chemistry of Makeup Today I/we will be discussing what exactly is going on in our makeup chemically. 

Segment 1: Introduction to Makeup Chemistry

What is Makeup?

• Cosmetics that are used to enhance or alter someone’s appearance
• Lipstick, eyeshadow, powders, and creams
• They contain water, emulsifier, preservative, thickener, emollient, colour, fragrance and pH stabilisers (buffers)
• The water dissolves other ingredients, it helps them mix together, acting as a solvent to dissolve other ingredients and forming emulsions for consistency. 
• Oil and wax help makeup go on smoothly, and is often used to help skin stay soft 
• Many other chemicals go into makeup. Normally, an emulsifier is included, a chemical that makes oil and water mix together or keeps unlike substances from separating
• Most makeup has preservatives, as well. These keep the makeup usable longer, preventing the growth of microorganisms such as bacteria and fungi, which can spoil the product and possibly harm the user; they can be natural or synthetic 
• Emollients soften the skin by preventing water loss. They are used in a wide range of lipsticks, lotions and cosmetics. 
• Thickening agents work to give products an appealing consistency from four families; lipid thickeners, naturally derived thickeners, mineral thickeners, and synthetic thickeners.
• Chemicals, both natural and synthetic, are added to cosmetics to provide an appealing fragrance. Even ‘unscented’ products may contain masking fragrances to mask the smell of other chemicals.
• Manufacturers do not have to list these individual fragrant ingredients or chemicals as fragrance is considered to be a trade secret.
• Many types of makeup also have a coloring agent. Any makeup with a color contains a coloring agent. These come from minerals, plants, and even animals.
• This is why some people have certain reactions to different colors of makeup as they may come from a source that the user is allergic to
• Ingredients can be naturally occurring or artificial, but any potential impact on our health depends mainly on the chemical compounds they are made of.

So Makeup can be Harmful?

• There is a lot of controversy as hundreds of internet sites relating to potentially toxic substances present in cosmetics and the dangers they pose to the public.
• These include parabens, aluminium, triclosan, formaldehyde, phthalates, and other possible chemicals that could affect someone’s skin condition or surface

Segment 2: The Chemistry Behind Specifically Lipstick

Now let’s go into the chemistry concepts specifically behind lipsticks. 

The chemical properties of water have a major role in lipstick

• Somewhat Universal Solvent: Water is used as a solvent in cosmetics and personal care products in which it dissolves many of the ingredients that impart skin benefits, such as conditioning agents and cleansing agents. It allows for addition for many ingredients in the products, and allows for them to be combined uniformly. 
• Water is a polar molecule with partially-positive and negative charges, it readily dissolves ions and polar molecules. It is therefore referred to as a solvent: a substance capable of dissolving other polar molecules and ionic compounds. The charges associated with these molecules form hydrogen bonds with water, surrounding the particle with water moleculesWhen ionic compounds are added to water, individual ions interact with the polar regions of the water molecules during the dissociation process, disrupting their ionic bonds.
• Since many biomolecules are either polar or charged, water readily dissolves these hydrophilic compounds. Water is a poor solvent for hydrophobic molecules such as lipids. Nonpolar molecules experience hydrophobic interactions in water: the water changes its hydrogen bonding patterns around the hydrophobic molecules.
• Like in the picture provided, you see how the negatively charged Cl- ion is attracting the positive sides of the water molecules
• Surface Tension: Water also forms emulsions in which the oil and water components of the product are combined to form creams and lotions, this is the emulsifier, it reduces the surface tensions between the oil and water, (hydrophobic and hydrophilic parts). These are sometimes referred to as oil-in-water emulsions or as water-in-oil depending on the ratios of the oil phase and water phase. 
• Surface tension is the property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules. In other words, the cohesiveness of the oil and water particles resist each other’s external forces from their surfaces, but the emulsifier breaks this or decreases the amount of force being exerted. 
• Emulsifier molecules work by having a hydrophilic end or a polar end(water-loving) and hydrophobic end or a nonpolar end (water-hating). The hydrophilic end of the emulsifier molecule is attracted to the water and the hydrophobic end is attracted to the fat/oil. By vigorously mixing the emulsifier with the water and fat/oil, a stable emulsion can be made.

Segment 3: Personal Connections

This topic interests me because I hope that one day I can create my own line of skincare and makeup products. It is my goal to create a line of products that is inclusive to everyone’s needs, that is vegan, cruelty free, and has little impact on the environment. I wanted to learn more about what goes into making makeup such as what determines its shelf-life, the color in creams, powders, and eyeshadows. In addition, how certain ingredients contribute to the state of matter of creams, how they are uniform with no clumps. If you really think about it there’s chemistry behind everything in makeup. This is important because we need to learn what is in the products that we use daily, and what we put on our faces. There are certain ingredients that can harm our skin, which I also find interesting that in small portions it wouldn’t harm us. 

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

• https://www.science.org.au/curious/people-medicine/chemistry-cosmetics
• https://wonderopolis.org/wonder/what-is-makeup-made-from#:~:text=So%2C%20what%20IS%20modern%20makeup,The%20water%20dissolves%20other%20ingredients.
• https://cosmeticsinfo.org/ingredient/water-0#:~:text=Water%20is%20primarily%20used%20as,to%20form%20creams%20and%20lotions.

Music Credits

Warm Nights by @LakeyInspired

Chemistry ConnectionsEpisode #6

Welcome to Chemistry Connections, my name is Kristen McDonough and I am your host for episode #6 called the chemistry of Fireworks. Today I will be discussing what a firework is composed of and how they give us a colorful display in the air. 

Segment 1: Introduction to Fireworks

What is a firework made of?

Fireworks are composed of 3 different components; oxidizers, fuel, and color. The components of a firework are located in an aerial shell. The shell is launched into the air with black powder. Time fuse located inside the shell which causes the explosion of the shell in the air to be delayed. Effect pellets located inside the shell determine the characteristics of the firework. Color is determined by how different elements react with the heat from the explosion. 

Segment 2: The Chemistry Behind Fireworks

Oxidizers are oxygen rich salts including potassium nitrate/perchlorate and strontium nitrate. 

Nitrates (NO3-) are used for the initial upwards thrust. Not all of the oxygen gas is released which results in a slower combustion. The most common nitrate is potassium nitrate, which decomposes to potassium oxide, nitrogen gas, and oxygen gas. Chlorates (ClO3- ions) release all of the oxygen atoms in the form of oxygen gas but are highly unstable and are not commonly used in fireworks. Perchlorates (ClO4-) are often used instead. They release all of the oxygen atoms in the form of gas but are more stable. Lewis dot structure reveals that chlorates have a lone pair electron bonded to the central atom, whereas perchlorates do not, explaining the difference in stability. 

The oxygen gas goes through a combination reaction with reducing agents such as sulfur and carbon otherwise known as the fuel. The fuel is a source of electrons, and in the reaction of oxygen gas and sulfur, sulfur dioxide is produced. The reaction is exothermic due to the greater energy released when the covalent bonds of the products are formed, resulting in the release of gas and heat causing the firework to explode 

The color of the fireworks are determined by the metal cations in the salts in the effect pellets. Copper oxide produces blue, Strontium chloride produces red, Sodium silicate produces yellow, Calcium carbonate or nitrate produces orange, Barium acetate produces green. 

Salts are used because they are easier to disperse and they’re less reactive compared to metals.  

The different metals have different amounts of electrons in their outer shell. When they react with energy in the form of heat, the electrons jump from the ground state to the excited state.

The electrons release energy in the form of light when returning from the excited state to ground state, and the amount of energy they release determines the color. High energy released results in short wavelengths and a more blue violet color, whereas low energy released results in longer wavelengths and amore red orange color. 

Segment 3: Personal Connections

Every fourth of July my family and I watch a fireworks display on the beach and we always have a lot of fun. Most people love the joy that fireworks give, so learning the chemistry behind fireworks has allowed me to connect my favorite holiday to chemistry. 

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

https://www.youtube.com/watch?v=nPHegSulI_M 

https://www.youtube.com/watch?v=qnA-rH1jwKA 

http://www.scifun.org/CHEMWEEK/fireworks/Fireworks2017.htm 

https://penntoday.upenn.edu/news/chemistry-behind-fireworks#:~:text=A%20standard%20firework%20has%20a%20fuel%2C%20oxidizer%2C%20and%20binder.&text=A%20chemical%20reaction%2C%20typically%20combustion,from%20one%20to%20the%20other. 

Music Credits

Warm Nights by @LakeyInspired 

Chemistry ConnectionsEpisode #5 

Welcome to Chemistry Connections, my name is Brian Shen/Xavier Park and we are your host for episode 5 called The Chemistry of Lithium-ion Batteries. Today we will be discussing how lithium-ion batteries work, and how their environment affects them.

Segment 1: Introduction to Lithium-ion Batteries

Introduce the episode topic

Include definitions, vocabulary, interesting background information and context

Lithium Ion batteries are used in numerous applications from mobile devices to electric cars. They are currently the highest energy density batteries that are mass produced. In the past, Nickel Metal Hydride or Lead Acid batteries were common for any application requiring rechargeable batteries. 

Sounds like we’re dealing with some complex topics here. Let’s explain them a bit in case our listeners are getting overwhelmed.

Segment 2: The Chemistry Behind Lithium-ion Batteries

Have a natural transition into an example… no need to say “segment 2”

Provide detailed explanations of the chemistry that is related to your topic.

While these batteries might seem complicated, the chemistry behind them is still based on the same concepts of electrochemistry. It’s just like an electrochemical cell with an anode and a cathode. 

Lithium ions travel back and forth between the anode and cathode as the battery charges and discharges. 

The cell also consists of an electrolyte solution. This solution is usually a solution of lithium salts and a solvent. 

Is there any reason why they use lithium ions instead of other elements?

Since lithium ions are rather small compared to other elements, a lot of lithium can be stored in a small area which is why Li-ion batteries have such high energy densities compared to lead-acid batteries or nickel MH batteries, both larger elements. 

And there’s different types of lithium-ion batteries as well, right?

(LiFePO4 batteries)

• Known for extremely high charge and discharge rates due to their pool passed ion storage
• Many more cycles compared to other lithium batteries
• Used in some car batteries since they are able to provide the huge amount of current needed to start a car

They’re clearly quite practical, but one of the most frustrating things is when you go outside on a cold winter day and your phone battery instantly drops 20%.

Yeah, why is that? 

Because the electrochemical cells rely on chemical reactions to function, it is only natural that the cold weather would hinder their ability to work. 

It limits the ability for the forward reactions to take place, therefore reducing the amount of electrons transferring from the anode to the cathode. 

For similar reasons, this is why your phone’s battery may seem to be restored when it eventually warms up. 

Once it reaches a certain point, the chemical reactions resume taking place, thus continuing the functionality of the battery.

So now that we know that heat can help the batteries function, can heat also be detrimental?

Yes, actually. These electrochemical cells are sealed, so they are more or less closed systems in some ways. There are therefore pressures inside the cell, and we know from chemistry that heat introduced into a system tends to increase pressure because particle movement becomes more chaotic.

Oh, that’s a bit concerning, because batteries heat up by themselves during use. That explains why batteries have limits on how much current can flow through them. Usually higher capacity batteries have higher internal resistance while high current cells generally lower internal resistance. When the same amount of current is being drawn from a cell, the cell with lower IR will generate less heat and see a lower voltage drop.

Segment 3: Personal Connections

What interested you in this topic? Why is it important? Anything else you’d like to share.

Now I have to ask, why do you know all of this?

I am interested in this topic because I build my own Li-ion battery packs using individual 18650 cells. I’ve been able to create a battery inside of an ammo can that can store 2.7 kWh (1000w load for 2.7 hours). I’ve also taken cells apart to find many layers. Now I finally understand what each of those layers do and the chemistry behind it. 

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. 

Sources:

https://www.science.org.au/curious/technology-future/lithium-ion-batteries

https://www.livescience.com/61334-batteries-die-cold-weather.html 

Music Credits

Warm Nights by @LakeyInspired