14Nov 2014 by Vincent Summers 3 Comments

Why Electroless Plating and Electroplating?

Chemistry
[caption id="attachment_6370" align="alignright" width="440"] Nickel Plating[/caption] Many items need require a coating of metal. Such can be applied in a couple of ways. One way is electroless plating. Another way is electroplating. Chrome handles on car doors are plastic with a veneer of metal. When you look in a mirror, you see your reflection in a sheet of glass with a metal film on the back. If you wear gold eyeglasses, there is a super thin coat of gold over base metal. Most plating uses a water solution containing metal salts. If an electric source is used to deposit the plate, the process is electroplating. If no electric source is used, it is auto-catalytic or electroless plating. How do these work? We will discuss the basics, beginning with electroplating. Electroplating…
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13Nov 2014 by Vincent Summers No Comments

Hydrogen Bonding Effects at Various Levels

Chemistry
[caption id="attachment_6362" align="alignright" width="440"] Hydrogen Bonding - a DNA step.[/caption] Hydrogen bonding ranges from simple interactions to protein folding and the double helix of DNA. Atoms bond to each other in a variety of ways. Among these are ionic bonds. Ionic bonds feature electron transfer between atoms. Then there are covalent bonds. These share electrons between atoms. There are also and metallic bonds. These consist of a matrix of atoms interlaced with mobile valence electrons. In addition to these major forms of bonding, there are weaker yet highly important bond types. Foremost of these are hydrogen bonds. Description A hydrogen bond is a tenuous electrostatic attraction between an already bonded atom of hydrogen and a second (electronegative) atom. These two atoms can be located in the same molecule or different…
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12Nov 2014 by Vincent Summers 1 Comment

Inert Gas Compounds?

Chemistry
[caption id="attachment_16914" align="alignright" width="440"] Xenon Tetrafluoride[/caption] There are millions of compounds. Some of them are even inert gas compounds. We were taught in high school that there are special, inert gases in the Periodic Table. These include radon and krypton, and are found in the column furthest to the right of the table. But that was then. Now we will learn that not all of those gases are all that inert. In addition to being called inert, the far right column gases are sometimes called rare or noble gases. These gases have a completed outer shell of electrons. So it would seem they should have no tendency to gain or lose electrons. But just how true is that? Can inert gases form compounds? Platinum Hexafluoride Platinum hexafluoride is formed by…
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10Nov 2014 by Vincent Summers No Comments

What Are Hybrid Atomic Orbitals?

Chemistry
[caption id="attachment_6346" align="alignright" width="440"] Pre-hybridization 1s, 2s, 2px, 2py, and 2pz atomic orbitals.[/caption] An atom consists of two components - a nucleus and its orbiting electrons. Nuclei contain neutrons and protons bound together by nuclear force. Electrons travel in well-defined atomic orbitals outside the nucleus. Orbitals come in different shapes. They contain up to two electrons each. A collection of orbits forms an electron shell. Atoms can have more than one shell. Orbitals and shells are identified by letters and numbers. The details are beyond the scope of this article; however, atoms begin filling electron orbitals in the order, Orbitals: s, p, d, f... Shells: 1, 2, 3, 4... First Elements Thus the first ten elements fill their orbitals and shells, Hydrogen 1s¹ Helium 1s² Lithium 1s² 2s¹ Beryllium 1s²…
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07Nov 2014 by Vincent Summers No Comments

The Two Processes Called Electron Capture

Chemistry
[caption id="attachment_6340" align="alignright" width="440"] The Physics Process[/caption] There is not one, but two processes, called electron or e- capture. Atoms can be visualized as two parts. The central nucleus, an inner core of protons plus neutrons, and an external shell of electrons traveling in their various orbitals. Ordinary chemical processes involve the making or breaking of bonds between two or more atoms. These bonds involve the electrons and the openings that hold them. The physics process of e- capture is the penetration by an inner shell electron into the nucleus of a neutron rich atom. Absorption by one of the protons replaces it with a neutron. At the same time, a neutrino and an X-ray photon are emitted. What Defines an Element? Element identity is determined by the proton count…
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07Nov 2014 by Vincent Summers 4 Comments

What is a Hydronium Ion?

Chemistry
What is a hydronium ion? Water... Is there a more important or abundant liquid on the face of the earth? It possesses an amazing number of properties. It is essential to our very existence. Water is one of an extremely small number of substances (liquid ammonia is another) that expands and becomes lighter on freezing. Ice floats and forms an insulating, protective crust over underlying water. If ice sank rather and didn't float instead, the ponds and lakes of earth would completely freeze. All living things would die. Structure & Electrical Properties of Water Water's chemical formula is H2O. Occasionally it is written HOH or H–O–H. This way of writing the structure is convenient as long as one is aware of the shortcomings. Water is not a linear molecule. It…
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27Oct 2014 by Vincent Summers No Comments

Anhydrides – Inorganic and Organic

Chemistry
Anhydrides are compounds that are similar to other compounds from which one or more molecules of water has been eliminated. An anhydride must not be confused with an anhydrous compound. In an anhydrous compound, the water reactant from which it is formed includes water that is attached lightly by weak bonds. Water is not an inherent part of the molecule's structure. Consider cupric sulfate pentahydrate, CuSO₄•5H₂O. This is a blue, crystalline substance. It is a composite structure of one molecule of cupric sulfate and five weakly held molecules of water of crystallization. Those water molecules can be removed quite easily. Powdering the crystals and warming them in a drying oven produces CuSO₄. This anhydrous compound is nearly white. No, it is not an anhydride. Aluminum Oxide Aluminum oxide, Al₂O₃, is an…
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13Oct 2014 by Vincent Summers 1 Comment

The Molecular Structure of Sodium Metasilicate Anhydrous

Chemistry
The basic formula for sodium metasilicate (water glass) includes two sodium, one silicon, and three oxygen atoms. When it includes no trace of water, the meta-silicate is anhydrous. Its formula should then be Na2SiO3, right? Well, yes. But, to leave it at that would be less than truthful. Parts, Just Parts Sodium meta-silicate can be visualized in two parts. One part is the two sodium ions Na+, each with a +1 charge. The other part is the meta-silicate (SiO3)-2 with its minus two charge. Some atoms can link to form chains. These atoms include carbon, boron, and silicon. Silicon and oxygen atoms of sodium meta-silicate molecules form a polymeric, corner bonded tetrahedra complex. This complex appears as if it has sub-units of SiO4 (silicon atoms central in tetrahedra). Note the SiO4…
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22Aug 2014 by Vincent Summers No Comments

Explaining Saturation and Unsaturation

Chemistry
What is Saturation? What is Unsaturation? Even those scientifically uninclined use the words. Saturation, unsaturation, and polyunsaturation are dietary terms closely associated with health. Most know they are also chemical terms. But they don't understand what they mean. This is a shame, since "saturation" can be easily understood by any bright student. Saturated Hydrocarbon Linkage Living matter (plant or animal) is made of of organic compounds. These include (but are not limited to) fats, carbohydrates, and proteins. All these substances contain a kind of backbone or chain, of atoms of carbon (C) bonded to atoms of hydrogen (H). Each carbon is capable of bonding with four hydrogens. [sc name="MidArticleAdsense"] For purposes of illustration, we'll assume we have before us a chain of four carbon atoms, with every available bond possibility…
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21Aug 2014 by Vincent Summers No Comments

Cubane: The Chemist’s Toy?

Chemistry
Cubane is an organic hydrocarbon. It consists of carbon and hydrogen and is cubic in shape. It is a very curious substance, indeed. With no practical purpose in view, it was first prepared in 1964. There is an endless number of theoretical molecular possibilities in the world of organic chemistry. Some chemicals are simple. Others are complex. Some are of practical use to mankind. Some are mere toys of the intellect. Yes, adults must have their toys! Cubism "We do the difficult immediately. The impossible takes a little time." Chemists enjoy challenges. One challenge was to synthesize cubane (C8H8). It is a cut with a carbon atom at each corner. Attached to each of them is one hydrogen atom (see the image). Now carbon "prefers" to form angles of 109.5…
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