Chemistry Archives - Page 3 of 22

06Jul 2019 by Vincent Summers 2 Comments

Adenosine Triphosphate (ATP) and Metabolism

Chemistry

In discussing the chemistry of the human body, the media features many important substances. Take water. We are told how important it is to drink lots of water. Our body cells do consist, after all, of about 60% water. And we repeatedly hear of DNA, cholesterol, free radicals, omega fatty-acids, trans fat and sodium. Yet, there is one essential compound that is seldom mentioned... adenosine triphosphate, acronym ATP. Have you heard-tell of ATP? No? Yet it is remarkably important – you could not exist without it. Besides, even if you could, the energy you'd need to function would be totally unavailable. ATP - What Is It? ATP, on examination (see image) is one molecule consisting of three portions. There is an adenine portion attached to a ribose (sugar) portion, attached…

01Jul 2019 by Vincent Summers 2 Comments

Anodizing Aluminum: How Can It Be Done?

Astronomy, Chemistry, Technology

Aluminum is a versatile metal, yet in order to be used in certain applications, it needs to be modified, improved. One way of modifying it is to add certain ingredients, such as a trace of copper, to toughen it. Another modification is the process of anodizing aluminum. What does that refer to? Anode & Cathode We're all familiar with electroplating. We may have eaten meals using silver-plate utensils. Or we may have attended a classic auto show in which older cars have chrome-plated bumpers. A metal coating (plating) from a chemical bath is applied using electricity to transfer the metal from a supply source (the anode) to the object to be plated (the cathode). The simplified artwork below illustrates a copper bath, complete with anode, cathode, and plating solution. A…

30Jun 2019 by Vincent Summers 1 Comment

Explosives: Nitrogen-Containing Fulminates

Chemistry

Chemical explosives are unstable¹ solids (occasionally liquids) that decompose rapidly, releasing large quantities of gas. The sudden volume increase pushes violently against whatever contains the explosive, reducing it to shrapnel and releasing a thunderous noise. Many explosives are nitrogen-containing substances, such as trinitrotoluene (TNT), nitroglycerin, and the picrates. Additional historic explosives include the fulminates, and yes, fulminates contain nitrogen as well. The most famous fulminate is mercuric fulminate, officially named mercury(II) fulminate. Its chemical composition is, Hg(CNO)2 It consists of one mercury atom and two atoms each of carbon, nitrogen, and oxygen. In greater detail, it can be written, Hg+2(C≡N=O)2 or Hg+2(C≡N+–O-)2 Do Fulminates Remind You of Other Chemicals? Perhaps the anionic fulminate ion, –CNO- reminds you of the cyanate anion, –OCN- or isocyanate anion, –NCO? And well it should,…

20Jun 2019 by Vincent Summers 1 Comment

A Simple Valence Problem for a Beginning Chemistry Enthusiast

Chemistry, Education

It is not unusual for school systems to introduce students to chemistry by means of the Periodic Table of the Elements. The table is then broken down into sections: the metals, the non-metals, and the gases. Before long, the structure of the atom is discussed, including protons, neutrons, electrons, orbitals, shells, and valence. It is the last of these we will briefly discuss here – valence. First a very brief discussion, followed by examples, followed by a puzzling problem (to impart insight). Valence: A Simple Discussion Atoms, although containing positive protons and negative electrons, have a net charge of zero. They are electrically neutral. This means each lone atom has a number of electrons equal to its number of protons. For instance, a sodium atom¹ has 11 protons. It also…

15Jun 2019 by Vincent Summers 1 Comment

Tires to Lemons – Well, Not Exactly

Chemistry, Technology

Although individuals and governments fall far short of maintaining Earth's pristine qualities, many do desire to minimize waste and its first cousin, pollution. Although one admirable action would be to minimize production, another is to recycle the resultant wastes. The late 19th and early 20th centuries introduced industrialization, and with it mechanization. Part of the mechanization was the automobile. And part of the automobile was the automobile tire. Tires are constructed of rubber or rubber-related products. They wear out well before most automobiles wear out. The problem is: what to do with all those worn-out, used tires? Millions and millions of them. They do not readily break down on being exposed to the elements. How can they be recycled? One Problem with Tires Now What might happen if tires were…

03Jun 2019 by Vincent Summers No Comments

Chemistry Students: Remember the Water of Crystallization

Chemistry, Education

[caption id="attachment_24966" align="alignright" width="480"] Don't forget the water.[/caption] Chemicals are, for the most part, categorized into inorganic compounds and organic compounds. The expression "water of crystallization" is rarely applied to organic compounds, since most of them are not water soluble, and if they are, few even of those form crystals with water. What IS Water of Crystallization? A high percentage of water-soluble inorganic salts form crystals that include water in their crystal lattice. An example of a salt, with and without water of crystallization is cupric sulfate.1 Such salts, deprived of water content, are termed anhydrous. In our example, we might speak of copper sulfate anhydrous.2 Quantity of Water [caption id="attachment_24967" align="alignright" width="380"] Fine crystals of copper sulfate pentahydrate.[/caption] Hydrated copper sulfate includes 5 molecules of water in its crystalline…

29May 2019 by Vincent Summers 1 Comment

What are Oximes and How Are They Useful?

Chemistry

Many with even a casual chemistry acquaintance have heard of such compounds as hydrocarbons, alcohols, ethers, glycols, and so forth. But the majority have probably never heard of oximes. What are oximes? How are they formed? Are they useful? Hydroxylamine Ammonia's chemical formula is NH3. Structurally, it resembles a tripod. If one of its hydrogen atoms is replaced by an hydroxyl group, –OH, the result is hydroxylamine, NH2OH. Two Oxime Varieties Hydroxylamine combines with aldehydes1 or ketones2 to form aldoximes or ketoximes, respectively. These are two subclasses of oxime. For example, hydroxylamine combines with acetaldehyde... CH3–CHO + NH2–OH → CH3–C(H)=N–OH And hydroxylamine combines with dimethylketone... (CH3)2=O + NH2–OH → (CH3)2–C=N–OH Of course there are other synthetic pathways that can be employed to produce oximes. So the question becomes, Do oximes…

18May 2019 by Vincent Summers 1 Comment

What are Ammines (Not Amines)? How Are They of Interest?

Chemistry

[caption id="attachment_24754" align="alignright" width="480"] tetramminediaquacopper(II) ion[/caption] Although most of us are not chemists, we recognize certain chemical terms. Some terms are more familiar than others. We know orange juice, tomatoes, and vinegar are "acid" or acidic. Other terms are less familiar, such as "free radical". We've heard them, and we have a faint idea of what they mean, but we don't really understand what they are. Amines, we may realize, are in part responsible for the fishy odor we seek to eliminate when cooking. To the chemist, an amine is an organic compound that includes at least one –NH2 group. N is the symbol representing a nitrogen atom, and H represents hydrogen. The word amine reminds us of the word ammonia, and rightly so. Ammonia is familiar to us as…

15May 2019 by Vincent Summers 2 Comments

How Does Thioglycolate Hair Remover Work?

Biology, Chemistry

Hair: men bemoan its loss and women fret over its appearance. For decades during the 20th Century, women were enamored by the so-called permanent wave. The most common process for assuring permanency of a hairstyle obtained at the beauty parlor involved a chemical process involving thioglycolate. See, Permanent Wave: Chem-mystery of Curl. By Extension... Although this process was used, not to remove hair, but to beautify it, by extension, a closely related process has been used to eliminate hair that grows¹ in undesired places. Notice this chemical reaction that occurs when thioglycolate is used to remove hair². 2 HOOC-CH₂-SH + R-S-S-R → HOOC-CH₂-S-S-CH₂-COOH + 2 R-SH The above reaction reads: two thioglycolic acid molecules plus one cystine (disulfide hair bond) produces two dithioglycolic acid molecules and two cysteine molecules. To…

13May 2019 by Vincent Summers 1 Comment

Manufacturing Polyurethane Involves Diisocyanates: How Dangerous?

Chemistry, Health

You almost can't escape from it. In one form or other, it is nearly everywhere. What is that? Polyurethane. We will focus on polyurethane in furniture refinishing. Then we will discuss its manufacture, and how its manufacture is so dangerous. Furniture Refinishing Before Polyurethane When I was young, I assisted my father in refinishing furniture. First, we'd strip the old finish off. Then, we'd rub the piece with fine very sandpaper. But that wasn't good enough. So we followed that up by polishing the surface with clean, dry, soap-less steel wool. Next, we'd apply a choice stain with a cotton rag such as an old torn T-shirt. Once that dried, we'd apply a coating of shellac. Once that was completely dry, we varnished. However, a coating of varnish produced to…