28Nov 2014 by Vincent Summers No Comments

Surface Area and Adsorption

Mathematics
[caption id="attachment_6504" align="alignright" width="480"] Activated Carbon - CC-2.5 by Ravedave[/caption] Surface area? What's that? And how does it affect physical properties? There are two similar words in the English language: absorption and adsorption. While they are related, they are at the same time distinctly separate. Absorption, simply put, is sucking into the interior or volume of something. Water, for instance, is sucked into the volume of a sponge. The water is held throughout the sponge. Adsorption Adsorption is a surface phenomenon. A substance that is adsorbed is adsorbed onto the surface. It does not enter into the interior or volume of the adsorbing agent. The difference in these physical processes determines the most efficient form the absorbing or adsorbing agent should assume. [caption id="attachment_15070" align="alignright" width="340"] Zeolite Materials for Methane…
Read More
28Nov 2014 by Vincent Summers 3 Comments

Most Efficient Shape for Holding Liquids

Mathematics
[caption id="attachment_6496" align="alignright" width="440"] Spherical Bottle.[/caption] We store liquids in a bottle. So what is the most efficient shape that uses the least glass to store the most liquid? The volume of a sphere divided by its surface area represents the greatest ratio possible of any geometrical object. We want to use the least material to construct the vessel, while it holds the most. How shall we determine what best meets our requirements? Most Efficient Shape We determine what best meets our requirements by logic supported by mathematics. V/S (sphere) = 4/3пr3/4п€r2 = r/3 Use, for purposes of comparison and illustration, a cube, whose dimensions are "a" on a side. Then, since its surface area is the area of its six sides, V/S (cube) = a3/6a2 = a/6 Now since…
Read More
27Nov 2014 by Vincent Summers No Comments

LCAO MO Chemical Bonding Theory and Examples

Chemistry
[caption id="attachment_8903" align="alignright" width="440"] Antibonding sigma orbital.[/caption] LCAO MO The nature of the chemical bond has been of interest for hundreds of years. Theories have been developed to explain how atoms combine to form molecules. The most successful theory to date is the (L)inear (C)ombination of (A)tomic (O)rbitals - (M)olecular (O)rbitals or LCAO MO bonding theory. You've got it: yet another acronym. Atoms have nuclei. These contain protons and neutrons. Electrons travel around these nuclei. Orbitals are mathematical functions that describe their trajectories. As atoms form molecules, atomic orbitals combine to form molecular orbitals. Since orbital functions are described by the Schrödinger wave equation and that equation is linear, molecular orbitals can be described by the linear additive combining of atomic orbitals. Example of Hydrogen Ordinary hydrogen has one proton,…
Read More
26Nov 2014 by Vincent Summers 1 Comment

Yeast and Baking Powder Bread Dough

Chemistry, Food
[caption id="attachment_6469" align="alignright" width="440"] CC-SA 3.0 by Lou Sander[/caption] Have you ever made dough with yeast and baking powder? Bread is one of the staples of life. Some translations of the Bible read, "Give us this day our daily bread." Most bread is leavened bread. Leavening refers to an ingredient or ingredients designed to raise and lighten bread, through the incorporation of tiny gas bubbles throughout the dough. Dough rises through two mechanisms, employing yeast and baking powder. The first is a biological process, the second is a chemical process. Either procedure results in a delicious, decidedly edible product. Yeast Rolls Yeast rolls and other breads are raised by means of microscopic animals called yeast. Yeast combines oxygen from the air with carbohydrates such as glucose sugar to produce carbon…
Read More
21Nov 2014 by Vincent Summers No Comments

Esters: Their Structure and Preparation

Chemistry
Many esters may be directly prepared by reacting an alcohol with an organic acid.1 To better understand what an ester is, it is important to understand why carbon is so special. Carbon Bonds to Itself Frequently, inorganic compounds are relatively small structures. For instance, barium metal, Ba, reacts readily with chlorine gas, Cl2, to give barium chloride, BaCl2. Ba + Cl2 → BaCl2 Notice barium atoms do not join to each other to form a chain, ring, or some other complex structure. However, carbon – the main element of organic compounds – can and often does bond to itself, forming larger molecules. For instance, diethyl ether is written, H3C-CH2-O-CH2-CH3 Two of the carbon atoms on the left are bonded to one another, as are the two on the right. In fact, chains and…
Read More
17Nov 2014 by Vincent Summers No Comments

Introduction to Polar Coordinates

Mathematics
[caption id="attachment_25281" align="alignright" width="403"] Polar rose: r = 2 sin (4*θ)[/caption]Frequently used in analytical geometry is the standard 2-dimensional x, y coordinate system called the Cartesian coordinate system (named after famous mathematician, René Descartes). It's time to branch out to a different system, the polar coordinates system. In fact, there are any of a number of ways of locating points in 2-D space. Conversion from Cartesian Coordinates The polar coordinates system utilizes an angle and a radius. It is relatively simple to change from the x-y system to an r-θ system. Drawing a circle centered at the origin on an x-y plane and then drawing a right triangle with the radius of the circle equaling r, then by definition, the side adjacent to the angle divided by the hypotenuse (longest…
Read More
17Nov 2014 by Vincent Summers No Comments

Keto Enol Tautomerism

Chemistry
Is the term keto enol tautomerism familiar to you? If not, give attention to the ensuing discussion. Organic chemistry would be of no value if not for multiple bonds and functional groups.  Such groups impart the reactivity needed to sustain life. One attachment is carbonyl (–C=O). Tautomerism Given the right environment, atoms of a carbonyl group tautomerize. That is, they can exchange a proton (hydrogen). In so doing a π-bond is formed or disappears. The carbonyl or keto form assumes the alkene-alcohol or enol form, or vice versa. For acetone, the two forms are, CH3–(C=O)–CH3 keto form CH2=C(OH)–CH3 enol form See the image above. [sc name="MidArticleAdsense"] Both Aldehydes and Ketones Participate A ketone has its carbonyl carbon atom linked to two other carbon atoms. An aldehyde has its carbonyl carbon…
Read More
16Nov 2014 by Vincent Summers 1 Comment

The Zwitterion – Nature, Occurrence, Ongoing Research

Chemistry
What in the world is a zwitterion? What is its importance? Molecules are bonded atoms that act as a unit. They are electrically balanced. This means they contain a total number of electrons equal to the number of protons. If a chemical structure does not possess an equal number of electrons and protons it is an ion. Molecules as a unit are electrically neutral. However, there may be local charges due to geometry or electronegativity. These charges are mostly less than that of a proton or electron. There is an exception. It is the zwitterion. This kind of ion has a full positive and a full negative charge. In organic chemistry there may be an alkyl backbone consisting of carbon (C) and hydrogen (H). Other groups (pendant groups) include hydroxyl,…
Read More
16Nov 2014 by Vincent Summers 1 Comment

Organic Chemistry: What is Ring Strain?

Chemistry
[caption id="attachment_16313" align="alignright" width="440"] Cyclopropane suffers from ring strain.[/caption] Carbon ring strain? What is that? Let's begin at the beginning. The element carbon is one of a small number of elements that can bond to itself repeatedly. Compare gases such as oxygen (O2), called diatomic gases because generally only two atoms unite. Oxygen is exceptional in that it does form the triatomic molecule, ozone (O3). However, carbon can form even lengthy chains. Thus, carbon can form, not only methane (CH4), but ethane (H3C-CH3), propane (H3C-CH2-CH3), butane (H3C-CH2-CH2-CH3), pentane (H3C-CH2-CH2-CH2-CH3), and so on. Curiously, carbon can also close those chains to form rings, much as a woman can close a string of pearls about her neck using a clasp. [sc name="MidArticleAdsense"] Cyclization Although methane cannot so close, nor can ethane, the…
Read More
16Nov 2014 by Vincent Summers No Comments

Organic Chemistry: What is a Lactam?

Chemistry
Most have never heard of a lactam. What is it? How can it be produced? Compounds are chemicals formed by combining two or more different atoms, the basic building blocks of matter. Organic compounds contain carbon, frequently bonded to itself, whether in chains, rings, or some other geometric structure. There are so many organic compounds, they must be categorized according to "functional groups." Functional groups are specialized structures within a compound that may contain a special atom, such as nitrogen, sulfur, phosphorous, etc. One kind of compound categorized by functional group is an amide. An amide results when an organic acid group reacts with a nitrogen-containing amine group and loses water. A lactam is a special kind of amide. It may serve as an intermediate in forming heterocyclic rings. Inorganic…
Read More