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This page links you to up-to-date Chemistry related news, topics, academic papers, reviews, research projects etc. Please let us know of any particularly interesting article links that you would recommend to other members.
About Chemistry
This Day in Science History - February 6 - Joseph Priestley
February 6th marks the passing of Joseph Priestley. Priestley was an English theologian and natural philosopher who is best known with this experimental works with gases or "airs". He was the first to identify several gases including the element oxygen. This discovery helped answer the old question: Why do things burn? The prevailing theory of the time held there was a substance present in all things called phlogiston. Things would burn until they become saturated with phlogiston and any fire would go out. Priestley's found his new air greatly increased the process of burning and called it "dephlogisticated air" since it appeared to contain no phlogiston. Even though his discovery seemed to support the phlogiston theory, it was one of the key elements to launch Lavoisier's chemical reaction theories that started the Chemical revolution of the 19th Century.
Priestley began his work with gases with a ready supply of phlogistated air, or carbon dioxide. He obtained near limitless supplies from a brewery near his ministry. One of the most notable achievements from this was a process to easily create carbonated water. Enjoy a carbonated beverage in honor of Priestley and find out what else occurred on this day in science history.
This Day in Science History - February 6 - Joseph Priestley originally appeared on About.com Chemistry on Sunday, February 5th, 2012 at 22:05:31.
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Quick Emulsifier Chemistry Demonstration
Soap is good at cleaning because it acts as an emulsifier, enabling one liquid to disperse into another immiscible liquid. While oil (which attracts dirt) doesn't naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed.
It's easy to demonstrate the action of an emulsifer. All you need are two immiscible liquids and a little dishwashing detergent or soap.
Emulsifier Demo Materials
- water
- kerosene or oil
- dishwashing detergent or soap
- flask or clear glass
- Add some kerosene or oil together with some water in a flask. Swirl the contents around to try to mix them. What happens?
- Add a squirt of dishwashing liquid. Swirl or shake the flask to mix the ingredients. How has the layer of kerosene or oil been changed?
More Emulsifier Demonstrations
Milk Color Wheel Demo
Pepper and Water Trick
Quick Emulsifier Chemistry Demonstration originally appeared on About.com Chemistry on Sunday, February 5th, 2012 at 21:39:51.
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How Febreze Works
The other day I got frozen tiny shrimp to feed the jellyfish and pipefish in my aquarium. I used my fingers to drop a pinchful of shrimp into the water, which worked great except I smelled like I just got off a shrimp boat. Soap didn't touch the stink. Neither did stainless steel. So, I decided to Febreze myself. It worked great. Initially I smelled like flowers instead of shrimp, but the floral smell washed off, leaving my hands unscented.
Have you wondered whether Febreze actually removes odors or whether it just covers them with a perfume? Have you wondered how it works? Here's the lowdown on Febreze. It's a product that was invented by Procter & Gamble and introduced in 1996. The active ingredient in Febreze is beta-cyclodextrin, a carbohydrate. Beta-cyclodextrin is an 8-sugar ringed molecule that is formed via an enzymatic conversion of starch. The cyclodextrin molecule sort of resembles a donut. When you spray Febreze, the water in the product partially dissolves the odor, allowing it to form a complex inside the 'hole' of the cyclodextrin donut shape. The stink molecule is still there, but it can't bind to your odor receptors, so you can't smell it. Depending on the type of Febreze you're using, the odor might simply be deactivated or it might be replaced with something nice-smelling, like a fruity or floral fragrance. As Febreze dries, more and more of the odor molecules bind to the cyclodextrin, lowering the concentration of the molecules in air and eliminating the odor. If water is added once again, the odor molecules are released, allowing them to be washed away and truly removed.
How Febreze Works originally appeared on About.com Chemistry on Sunday, February 5th, 2012 at 17:00:27.
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This Day in Science History - February 5 - Indiana Pi Law
On February 5, 1897, the Indiana General Assembly voted unanimously to pass a bill set the value of π equal to 3.2. The bill actually dealt with issues behind an old geometrical puzzle involving squaring a circle. Is it possible to create a square with the same area as a circle in finite steps using only a compass and straightedge.
An Indiana amateur mathematician named Edwin Goodwin believed he had discovered the elusive solution to this problem. He approached his state representative, Taylor Record with an idea that would gain him recognition for his achievement, and help his home state out in the process. Record introduced bill #246:
A Bill for an act introducing a new mathematical truth and offered as a contribution to education to be used only by the State of Indiana free of cost by paying any royalties whatever on the same, provided it is accepted and adopted by the official action of the Legislature of 1897.If Indiana would accept the validity of his work, Goodwin would allow the state to use his discovery in school textbooks free of charge, while the rest of the country would have to pay a royalty. The bill contained various mathematical steps to square the circle where one step involved the value of the ratio of the diameter and circumference (the definition of π) is as five-fourths to four, or 3.2.
Fortunately, this vote took place the same day the head of Perdue University's Mathematics Department, Clarence Waldo was at the statehouse securing funds for the University's budget. When he heard the assembly was discussing mathematics, he listened in and was amazed. He spent the rest of the day educating Indiana senators on geometry and properties of transcendental numbers. His lessons were effective enough that the bill died on the Senate floor on February 11.
Find out what else occurred on this day in science history.
This Day in Science History - February 5 - Indiana Pi Law originally appeared on About.com Chemistry on Saturday, February 4th, 2012 at 22:05:06.
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Xylitol May Be Deadly to Dogs
Many dog owners are aware that chocolate, coffee, and grapes are toxic to dogs, but did you know about the risk from ingesting the common sweetener, xylitol? Xylitol is a natural sweetener that is found in a variety of products, including chewing gum, toothpaste, candy, chewable vitamins, and sugar-free baked goods. While xylitol is not toxic to humans, it can be deadly to dogs. Ingesting 100 milligram of xylitol per kilogram of bodyweight may cause life-threatening hypoglycemia (low blood sugar). The drop in blood sugar occurs within 15 minutes while the symptoms of hypoglycemia (depression, loss of coordination, seizures, coma) may be seen within 30 minutes after the dog eats the xylitol-containing product. Exposure to higher doses of xylitol may result in fatal liver failure.
Since the toxic dose depends on body weight, it is difficult to say how much xylitol the dog would have to eat in order for it to be at risk. According to Snopes, the lethal dose for a 65 lb dog might be contained in 8-10 pieces of gum, with as little as 2-3 sticks of gum causing a lethal drop in blood sugar in a 20 lb dog. Because the effects from the xylitol are experienced so quickly and it is so difficult to gauge the dose, dog owners should contact their veterinarian immediately if their dog has eaten a product which contains xylitol. You may be instructed to induce vomiting and to bring the dog in to have its blood sugar checked. The usual treatment is to provide intravenous glucose. The dog may be permitted to return home once insulin values have returned to normal.
Xylitol May Be Deadly to Dogs originally appeared on About.com Chemistry on Saturday, February 4th, 2012 at 08:13:28.
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This Day in Science History - February 4 - Friedrich Hund and Hund's Rule
February 4th is Friedrich Hund's birthday. Hund was a German physicist who introduced a method to use molecular orbitals to determine electron structure of molecules and bonds. Hund's rules are a set of rules that determine the ground state of a multi-electron atom based on the energy levels of the filled orbitals.
Hund proposed a set of three rules electrons follow to fill up "shells" or orbitals in multiple electron atoms. In chemistry, only one rule is generally referred to as "Hund's Rule". This rule comes in to play when determining the electron configuration of an atom and the Aufbau principle. Hund's rule deals with the quantum number dealing with spin, s. The s quantum number has two possible values, +½ and -½, also known as "spin up" and "spin down". The rule states that in an orbital, electrons will fill all available positions of the same value of s before the opposite spin value appears.
Determining an atom or molecule's electronic structure can give useful insight as to how the atom or molecule will combine with other molecules or atoms. Find out what else occurred on this day in science history.
This Day in Science History - February 4 - Friedrich Hund and Hund's Rule originally appeared on About.com Chemistry on Friday, February 3rd, 2012 at 22:20:00.
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Friday Fire Project - Fire Magic Tricks
If one fire project is good, then more is better, right? I grouped together the fire projects that could be used as fire magic tricks, so you can play with fire and amaze your friends. Let me know if you're aware of any fire tricks that I haven't described. Have a great start to your weekend!
Play with fire...
Friday Fire Project - Fire Magic Tricks originally appeared on About.com Chemistry on Friday, February 3rd, 2012 at 12:24:21.
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Color Change Thermometer Project
Here's a color change project that will give you a liquid that fluctuates between pink and blue as the temperature changes.
What You Need
- beaker or attractive clear container
- 3 g cobalt(II) chloride hexahydrate (also known as cobaltous chloride hydrate)
- 500 ml alcohol
Prepare the Solution
- Mix 3 grams of cobalt(II) chloride hexahydrate in alcohol.
- The pink solution will turn blue as it is heated and will return to the pink color as the solution cools.
- Alternatively, heat the solution until it it is just slightly warmer than room temperature. Add water dropwise until the blue solution turns pink. This solution will be extremely sensitive to color changes near room temperature.
How It Works
Aqueous solutions of hydrated cobalt chloride are pink, but formation of [CoCl4]2- produces a blue color. Addition of hydrochloric acid to an aqueous cobalt(II) chloride solution will change the solution from pink to blue as will temperature change of the alcohol solution. This presumably occurs because the amount of water attached to the cobalt ion changes as you vary the temperature of the alcohol solution.Rainbow Wand | More Color Change Projects
Color Change Thermometer Project originally appeared on About.com Chemistry on Friday, February 3rd, 2012 at 07:41:36.
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This Day in Science History - February 3 - Space Race Firsts
February 3rd, 1966 was a day for two 'firsts' during the Space Race between the United States and Soviet Union. The United States launched the first meteorological satellite, the ESSA-1. ESSA-1 (Environmental Science Services Administration) would take photographs of cloud cover and transmit the data to the National Meteorological Center. It would be supplemented by 8 other ESSA satellites over the next three years and provided weather information to receiving stations in 45 different countries.
The Soviet Union successfully landed a probe on the surface of the Moon for the first soft landing on another celestial body. The Luna 9 spacecraft touched down and began taking photographs of the area around the landing site. Luna 9 was the second spacecraft to reach the moon after the Luna 2 probe crashed into the surface in 1959.
Find out what else occurred on this day in science history.
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This Day in Science History - February 3 - Space Race Firsts originally appeared on About.com Chemistry on Thursday, February 2nd, 2012 at 22:05:58.
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How to Make Blue Fire
Blue fire is extremely easy to make. Here are some ways you can make blue fire yourself.
Natural Blue Fire
The easiest way to make blue fire is to burn a chemical that naturally produces a blue flame. Most types of alcohol burn as blue fire, such as ethanol, methanol, and isopropyl alcohol. Natural gas also burns with a blue flame.- ethanol (e.g., rum, vodka)
- methanol (wood alcohol, Heet fuel treatment)
- isoproyl alcohol (rubbing alcohol)
- natural gas
Easy Method of Making Blue Fire
Several metal salts burn with a blue flame, such as certain copper, arsenic, and lead compounds. Antimony and lead are toxic, but you can use copper(I) chloride to produce blue fire. If you cannot locate copper chloride, it is possible to make this chemical yourself.- Add a small amount of water to copper(I) chloride to dissolve the salt.
- Soak a flammable material with the copper chloride solution. Good choices include sawdust or pinecones.
- Allow the material to dry. When you light it or add it to a normal fire you will get blue fire.
How to Make Blue Fire originally appeared on About.com Chemistry on Thursday, February 2nd, 2012 at 08:03:17.
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