This Friday, April 12, Chem Club will start exploring distillation using steam. Steam distillation is a well-known technique for extracting aromatic compounds from plants. Water vapor goes through freshly picked vegetable matter, such as flowers or leaves, and carries away most of the volatile fragrances. This distilled vapor is then condensed into a mixture of water and aromatic oils. The separated essential plant oils can be used to make various products, such as flower waters, candles, or bath bombs.
Chem Club will not meet this Friday, April 5, due to the ALA Youth Rally and Night In Old Tech.
There will be no school on Friday, March 29, due to the Good Friday holiday.
Chem Club will continue to explore exothermic reactions on Friday, March 8, along with an endothermic reaction. Endothermic reactions, from a thermodynamic point-of-view, are fighting an uphill battle. Because of this, most endothermic reactions are not very impressive, unlike the dramatic demonstrations of exothermic reactions.
However, here is a dramatic example of a spontaneous endothermic reaction. Solid barium hydroxide octahydrate, Ba(OH)2•8H2O, and ammonium thiocyanate, NH4SCN, are mixed in a beaker, which is then placed on a few drops of water on a small board. The reaction that occurs is highly endothermic, and it causes the beaker to freeze to the board. The low temperature (below 0oC) is read by a digital thermometer. The gas produced by the reaction is shown to be basic by the use of pH paper. The equation for the reaction is given.
When the temperature is measured it has dropped to between negative 20 and negative 30 degrees Celsius so the temperature is well below the freezing point of water. The equation for the reaction shows that barium thiocyanate, ammonia gas, and liquid water are formed by the reaction of the solid barium hydroxide and the solid ammonium thiocyanate.
The equation for the reaction is:
Ba(OH)2.8H2O(s) + 2 NH4SCN(s) &arr Ba(SCN)2(s) + 10 H2O(l) + 2 NH3(g)
This Friday, March 1, Chem Club will further explore exothermic reactions and look at rockets which use sugar as a fuel and potassium chlorate as an oxidizer. When you heat solid potassium chlorate, it decomposes and produces molten potassium chloride and oxygen gas.
2 KClO3 (l) → 2 KCl (l) + 3 O2 (g)
When you add a hydrocarbon such as sugar to the molten potassium chlorate, a combustion reaction occurs between the sucrose and the oxygen which was produced in the decomposition reaction.
C12H22O11 (s) + 12 O2 (g) → 12 CO2 (g) + 11 H2O (g) + energy
The combustion reaction is very exothermic, and produces large amounts of light, heat, and combustion products. The lilac-colored flame is characteristic of the emission color of potassium, the color of which we have identified from previous flame tests of alkali metals.
This Friday, February 23, Chem Club will explore exothermic reactions. Specifically, how those flameless heaters found in military rations and in some camping meals work.
Ration heaters generate heat in an oxidation-reduction reaction. Water oxidizes magnesium metal in an electron-transfer process, using the following chemical reaction:
Mg + 2H2O → Mg(OH)2 + H2 + heat
This reaction is similar to oxygen rusting iron, and happens at about the same slow rate. This rate is too slow to generate any useful heat. To speed up the reaction, table salt and iron particles are mixed in with the magnesium particles. After adding about 30 mL of water to a flameless ration heater, the temperature of a 230-g meal package rises by 38°C in about 10 minutes.
We will explore the chemical reaction of the flameless ration heater, use it to heat up some military pizza, and then make our own (the heater, not the pizza).
Chem Club will not meet on Friday, February 9, nor Friday, February 16, because of ALA student holidays. We shall meet the following week on February 23.
Chem Club will meet on Friday, February 2, to explore combustion reactions. Specifically, the combustion of methane.
Soap bubbles containing methane will rise because methane, CH4, or natural gas, is lighter than air. The balanced equation for the combustion of methane in air is:
CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) ΔH = - 864 kJ/mole
Like all other hydrocarbons, the complete combustion of methane produces the same products: carbon dioxide and water. And a lot of heat.
Chem Club will not meet on Friday, January 26, because of our Academic Decathlon regional tournament that weekend. We shall meet the following week.
It looks like that Chem Club will not meet on Friday, January 19. The district has decided that there will be no school on Thursday, January 18, and Friday, January 19, due to the winter weather.
Chem Club will not meet on Friday, January 12, because of our Academic Decathlon tournament that weekend. We shall meet the following week.
Chem Club will not meet on Friday, December 15. The 10th grade travel experiences to Puebla, Mexico are happening December 10 through 15.
Students will be on Winter break from December 18, 2023 through January 2, 2024. Happy Holidays!
This Friday, December 8, we shall make silver ornaments for the holidays!
We shall not meet next week, December 15, because the 10th grade will have their travel experiences in Puebla, Mexico. After then, students will be on Winter break from December 18, 2023 through January 2, 2024.
In 1835, Justus von Liebig invented a process to plate a glass sheet with a thin layer of silver metal by using dextrose. This easy method of lining glass with a silver mirror started the modern industry of producing common household mirrors.
Chem Club will use Liebig's silver mirror reaction to make silver holiday ornaments. This oxidation–reduction reaction is between silver complex ions and dextrose in an ammonia solution. Dextrose, also known as glucose, is a simple carbohydrate. It is an example of a reducing sugar, because it can react with and reduce oxidizing agents such as Ag+1 or Cu+2 ions. Dextrose molecules reduce Ag(NH3)2+ complex ions to form silver metal, which plates out as a thin layer on the inside of the glass ornament. The chemical reaction is as follows:
R–CHO(aq) + 2Ag(NH3)2+(aq) + 2OH–(aq) → R–COO–(aq) + 2Ag(s) + NH4+(aq) + 3NH3(aq) + H2O(l)
This Friday, December 1, Chem Club will be making bath bombs. Bath bombs are basically a mixture of baking soda and citric acid. When dropped in water, the sodium bicarbonate (baking soda) and citric acid react to make carbon dioxide gas, which makes the bath bomb fizzy. Since sodium bicarbonate is a weak base and citric acid is a weak acid, this is called an acid-base reaction.
Chem Club will have our Thanksgiving Party on Friday, November 17. We will not have school November 20-24 for Thanksgiving break. I hope everyone gets some rest and enjoys their time with family and friends.
As our thoughts turn toward the roast turkey, we usually start a conversation about why we get sleepy after the Thanksgiving feast. The blame usually goes to tryptophan.
Tryptophan, C11H12N2O2, or more formally (2S)-2-amino-3-(1H-indol-3-yl)propanoic acid is an amino acid that contains an α-amino group, an α-carboxylic acid group, and a side-chain indole. Sure, it's found in turkey, but it is also in eggs, salmon, and dairy products. Although everyone thinks turkey has a ton of tryptophan, gram for gram, cheddar cheese has more tryptophan.
Yes, it's true that tryptophan helps our body make serotonin and melatonin, which helps us sleep, but the post-Thanksgiving nap is more likely a result of all that carbohydrate we are stuffing ourselves with. Carbohydrates make our pancreas release insulin to regulate the amount of glucose in our blood. The huge load of carbohydrates and sugars that we eat results in a higher dose of insulin. This causes a drop in our blood sugar, which lowers our energy. And that makes us feel sleepy.
So, if you don't want to crash after the feast, have some more turkey and a little less of the pumpkin pie and mac and cheese.
Chem Club will meet on Friday, November 10, to discuss our Thanksgiving Party next week.
Our Noche Musical de los Muertos fundraiser last Thursday, October 26, was a great success! The ALA fundraiser made over $14,000 for our PK-12 campus to help support clubs, organizations, and field trips. Chem Club sold out of our slime and almost sold out of our scented candles! Many thanks for everyone's hard work to make Chem Club a success!
This Friday, November 3, Chem Club will take a breather and discuss what we would like to do for the holiday season.
This Friday, October 20, is a student holiday, so we will not meet. Instead, Chem Club will meet at our booth this Thursday, October 26, for our Noche Musical de los Muertos fundraiser from 5:00 to 9:00 PM. We will continue to get ready this week and plan on offering four different holiday-scented candles during the fundraiser.
Besides during our club time on Friday, October 20, Chem Club will start making candles this week for our fundraiser at the upcoming Noche Musical de los Muertos on Thursday, October 26. We plan on offering four different holiday-scented candles during the fundraiser.
This Friday, October 13, Chem Club will discuss how the candles turned out and begin making candles for our fundraiser!
This Friday, October 6, Chem Club will meet to discuss how to make candles, which is a combustion reaction, thus: Fuel + O2 → CO2 + H2O. We will explore the best mix of wax, color, and fragrance.
Join us this Friday, September 29, for the first meeting of Chem Club for the 2023-2024 school year. We will meet in Mr. Glass's room after school from 4:05 to 5:05 PM. We shall discuss Chem Club norms, volunteer for upcoming events, and choose club officers.