Bond Chemical Delokal dan Resonance

Delokal bonding found in compounds containing unsaturated one or more bonding orbitals are not limited to the two atoms, but spread up to three atoms or more. Such a bond is called bond delokal. In the valence bond method, to describe the actual structure of Such molecules, several Lewis structures (canonical form) is written, then taken their average weight. The weight of an average of two or more forms called resonance.

Bond Energy

There are two types of binding energy. The energy required to break a bond produce the radical is called dissociation energy D. For example D for H2O → HO + H is 118 kcal / mol. However, this value is not selected as the binding energy OH in water because of D for HO → H + O is 100 kcal / mol. The average of these two values The (109 kcal / mol) was chosen as the binding energy E. For methane, the total energy change of CH4 into C + 4H (at 0 K) is 393 kcal / mol. This means E for the CH bond in methane is 98 kcal / mol at 0 K. In the molecular diatoms, of course D = E. The heat of combustion is known exactly is burning hothydrocarbons. For methane, combustion heat value at 25oC was 212.8 kcal / mol, which leads to heat atomisasinya value is 398.0 kcal / mol (At 25oC), or the value of E for CH bond is 99.5 kcal / mole at 25oC.  

Bond angle

Sp3 carbon bond angle can be expected is always equal to the tetrahedral 109o28 ', but this can only happen if the four clusters are bound are identical as in methane, neopentana, or carbon tetrachloride. Most cases are found where there has been little deviation from the angles in pure tetrahedarl. As examples of CC-Br angles in 2-bromopropana is 114.2 o. A similar found deviations from the point of 120o to 180o angle to sp2 and sp. This deviation occurs because of slight differences hybridization.

Long bond

The distance between the atoms in the molecule is characteristic of molecules and can provide valuable information when compared with the same bond in different molecules.

The primary method of determining the bond length and angle is the x-ray diffraction (for solids), electron diffraction (only for gas), and methods spektroskofi.

Induction and Field Effects

CC bond in ethane is perfect because the bond is nonpolar connecting the two atoms are equivalent. However, the C-C bond in kloroetana polarized by the presence of electronegative chlorine atoms. This polarization is actually the sum of two effects.

Covalent Molecules Ionic Character

It is known that in the bond A - B where A and B have differences in electronegativity, the bond is purely covalent. As an example we using hydrochloric acid. 

Electronegativity

Electronegativity is a concept that is raised by chemists as the development of the phenomenon of a permanent dipole moment caused by asymmetric molecules. Electronegativity is defined as the latent power of an atom within a molecule to attract electrons. This concept depends on theoretical structure of modern organic chemistry to interpret some properties such as: strength of acidity and alkalinity, chemical bond lengths, ionic character, volatility, solubility, redox potential, hydrogen bond strength, and others.

Lewis Structure

The structure of molecules, ions, or free radicals which have only electron possible localized written with a formula that shows the location of electrons, and called Lewis structures. This formula shows only valence electrons, both found in the covalent bond that links two atom, or as free electrons. The structure of a molecule must be written with true because the position of the electron can change in a reaction, and it is important to know the initial position of the electron prior to drill down to where berpindahannya. For can write the formula of a molecular electronics properly it is necessary to apply

rules as follows:

A STUDY OF ELECTRONIC STRUCTURE OF AZOBENZENE MOLECULE AND ITS DERIVATIVES

Azobenzene-based conjugate of organic molecules have been known to have a large second order nonlinear optical properties. With this property, the molecules have a promise of potential to be developed into variety photonics devices, Such as optical switching, optical memory, as well as grating. A variation of the nonlinear properties of the molecules cans be controlled by choosing a Suitable of Donor-Acceptor That group attached on both sides of azo dyes. Hence, the study of the molecular structure is Important. Through this study, the Correlation Between its molecular structure and physical properties of cans be found. One of the Important methods to analyze the information about molecular structure is UV / Vis spectroscopy.

Multiple bond

If the ethylene molecules are reviewed according to the concept of molecular orbitals, carbon in the molecule using sp2 orbital to form bonds with three other atoms. Orbital hybridisation sp2 emerged from 2s1, 2px1, and 2py1. Each of the three carbon atoms of ethylene binding through σ bonds, one to each hydrogen atom, and one to the other carbon. Each carbon atom has one electron in the 2pz orbital, and based on the principle of maximum repulsion then the orbital is perpendicular to the plane of sp2 orbitals. Two parallel 2pz orbitals overlap laterally to produce two new hybrid orbitals, the π bonding orbital and orbital anti-bonding π *. Orbital σ ellipsoid-shaped and symmetrical around the axis CC.orbitals Π in the form of two ellipsoid, one above and one below. Own field declared node.

ties in Carbon Compounds

Formation of the bond between two atoms is described by the progress of overlap atomic orbitals that form the bond. The greater the likelihood beroverlap the stronger the bond is also formed. Relative strength of the overlap between orbitals atom has been calculated as follows: 

Hybridization

A carbon atom bonded to four other atoms is not clear using an atomic orbitas 2s and three 2p atomic orbitals because it would lead to the formation of three bonds with the orientation direction perpendicular to each other and a bond that has no direction of orientation.

Multivalensi

An atom has only one orbital univalensi who are willing to binding, but the atoms with two valence or more must form bonds by using at least two orbitals. Orbitals of oxygen atom has two half-full to make the atom valency two. Orbital is formed single bond through two atomic orbitals overlap with another.

Molecular Orbital Model

Problems arise from the calculation of the electron distribution of settlement allowed for the Schrodinger equation of quantum mechanics, in which each  settlement is known as a molecular orbital (MO) and related particular energy states and the distribution of electron pairs. In the orbital method molecule, the bond is considered formed from the atomic orbitals overlap.

Nitrogen Excretion In The Urine

Research conducted by experts on the mechanisms of nitrogen fixation reaction using only a pimple roots and bacterial nitrogen catcher. The results of their research is that the nitrogen captured from the air by the bodies had been converted into ammonia. This means that in the body is held hydrogenation or reduction system. Not only N - N are reduced to NH 3 but other compounds such as acetylene, cyanide, and azide can also be reduced by fastening the body of nitrogen. Therefore, in the process of hydrogen or electrons needed to reduce it in such a system must have a compound that acts as hydrogen or electron donor.

Giving Names Alkane Alcohols

Hydroxyl group on carbon - Philip McIntosh

Alcohol is a heterogeneous class of organic compounds. All alcohol contains one or more hydroxyl (OH) groups. Ethanol (ethyl alcohol) is the most famous member of the family.

The alcohol has a special place in the history of chemistry and the history of mankind. Ethyl alcohol is the most popular drug of all time, and cause of joy and tragedy. From the perspective of alcohol chemists offer various possibilities for the study and synthesis of new and valuable connections.

Digestive System

Food digestion system consisting of the oral cavity, pharynx, esophagus, stomach, small intestine and colon. The process of digestion is the process of mixing and breakdown of food by some secretion which takes place in all the existing channels in the body. Chemically, digestion is the process of hydrolysis behan food into molecules that are smaller, which then used the bodies of living.

Isolation Of Enzyme Bromelin

The enzyme is known for the first time as a protein by Summer in 1926 that has managed to isolate urease from 'kara sword' (jack bean). Urease is an enzyme which can outline of urea to CO2 and NH3. Northop than few years and Kunitz to isolate pepsin, trypsin, chymotrypsin.

Testing Of Wheat Flour And The Color Reaction

The way the work done on the testing of wheat flour and the color reaction is:

The first is test of wheat flour have 2 experiment.

Fat stain test. Testing menggojok fat with a little flour with the ester, and then test the air-ether solution of the fat with osmiat acid and observed results.

Valence bond

A molecule containing certain atoms located in the space.One part of the molecule position can be determined which of course is the nucleus (Anpat alisis obtained through X-ray diffraction by crystals), whereas the can not be determined is the electron bonds that position change then followed addition of one electron to the atom.

Covalency and Molecular Structure

An understanding of chemical reactivity begins with the understanding of chemical bonds, that is the style that makes a set of certain atoms (better known as molecule) that is more stable than others. Under these conditions, reaction or chemical bonding changes can be approached and used the theory of organic chemistry rational and consistent.

Urease Enzyme

The enzyme is a functional unit of cell metabolism. Working with an orderly sequence, the enzyme catalyzes the reaction gradually describing hundreds of nutrient molecules, reactions which store and convert chemical energy, and that makes the macro molecular pre cursor cells from simple. Among a number of enzymes that participate, there is a special group of enzymes known as the regulator, which can recognize various cues metabolic and catalytic change speed in accordance with the received signal. Through its activities, well-coordinated enzyme systems, resulting in a harmonious relationship among a number of different metabolic activities, which are required to sustain life.

Learning Everyday: MENULIS RUMUS STRUKTUR KIMIA ORGANIK

Learning Everyday: MENULIS RUMUS STRUKTUR KIMIA ORGANIK

Theory Of Structure Of Organic Molecules

Studies of organic chemistry must arrive at the molecular level, due to physical and chemical properties of compounds described in the structure and bonding of molecules. Four elements, hydrogen, carbon, oxygen, and nitrogen is a key element of organic compounds. Therefore, our understanding of organic chemistry must start from the electron structure and properties of these elements.

There are three theories to describe the structure of organic molecules :

Chemical Bond

1. Ionic bond

Ionic bond (or bond elektrokovalen) is a type of chemical bonds that can be formed between the ion-ionlogam dengannon-metal (or polyatomic ions such as ammonium) through electrostatic attraction force. In other words, ionic bonds are formed from the force of attraction between two ions of different charge.For example in table salt (sodium chloride).

Intermolecular Forces

Intermolecular forces are the electromagnetic force that occurs etween widely separated parts of a macro-molecule. These forces of cohesion Between cans similar molecules, Such as for example the surface tension, or the adhesion between unlike molecules, for example on capillarity. These forces, starting from the most powerful, consisting of: ionic interactions, bond hydrogen, dipole interaction (dipole), and Van der Waals force.

1. Hydrogen bond

In chemistry, hydrogen bonding is a type of intermolecular attractive force that occurs between two partial electric charges with opposite polarity. Although stronger than most of the intermolecular forces, hydrogen bonding is much weaker than covalent bonds and ionic bonds. In macromolecules such as proteins and nucleic acids, this bonding can occur between two parts of the molecule the same. and acts as a determinant of overall molecular shape important. Hydrogen bonding occurs when a molecule has an atomic N, O, or F.which have a lone pair (lone pair electrons). Hydrogen from other molecules will interact with the lone pair form a hydrogen bond with large bond varies from weak (1-2 kJ mol-1) to high (> 155 kJ mol-1).Hydrogen bond strength is influenced by differences in electronegativity between atoms in the molecule. The bigger the difference, the greater the hydrogen bonds are formed.Hydrogen bonds affect the boiling point of a compound. The more hydrogen bond, the higher the boiling point. However, specialized in water (H2O), there are two hydrogen bonds in each molecule. As a result the total number of hydrogen bonds is greater than the fluoride acid (HF), which should have the largest hydrogen bonding (because the highest electronegativity differences) so that the boiling point of water higher than the acid fluoride.

2. Style van der walls

Van der Waals force in chemistry refers to certain types of forces between molecules. This term originally refers to any type of forces between molecules, and it is still sometimes used in the sense that, but today more commonly refers to the forces arising from the polar ization of molecules into dipole. This includes forces that arise from permanent dipoles (Keesom forces), dipole rotation or free (Debye forces) as well as a shift in the distribution of awanel ektron (style London). The name of this style is taken from a Dutch chemist Johannes van der Waals forces, who first noted this type of style. Potential Lennard-Jonesseringused as a model approximation for van der Waals force as a function of time. Van der Waals interactions were observed on noble gas, which is very stable and tend not to interact. This explains the difficulty of the noble gases condense. However, the bigger the size of noble gas atoms (more electrons), the easier the gas turned into liquid.

2. Pull Style Dipoles

Molecules that have a permanent dipole moment said to be polar. Notice in the picture :

 

 Fig. Tri-atomic molecule polar and non polar 

Vector direction toward a more electronegative atom plus end shows to the less electronegative atom. Style attraction between two polar molecules called dipoles attraction Style. This attraction is stronger than the attraction between non-polar molecules.

   

 

Wheat Flour

Crop sorghum grain is often called, originated from Central Africa between Ethiopia and eastern Sudan. Wheat crops included in the family Graminaeae. The original name is not clear sorghum, known diIndia bicolor, East Africa by the name of infidel and Indonesia often called wheat.

Wheat crop have advantages compared with other Cereal crop resistance to drought. Drought resistant is caused by the wax coating on the stems and leaves, and relatively small surface of the leaf that can reduce water loss due to evaporation . Seeds of wheat has a quality comparable with corn meal. Wheat protein content is slightly higher than corn, while the lower-fat ingredient.

Seeds of wheat is composed of approximately 82% endosperm, 10% of institutions, 8% of the outer skin or perikarp. Outer skin is composed of three layers: epikarp, mesokarp, and endokarp. Below there is a layer Testa endokarp layer which contains tannin dyes. These compounds can cause coloring and bitter taste in our products and can react with proteins. Amylose content of wheat seeds contain 28.15%, protein 9.72% and 3.57% fat.

The content of wheat, among others: 1) Sorghum Starch. Based on the nature of the starch, can be divided into two kinds of types of Waxy (fluffier) contains very high amylopectin reached 100% and the type of non Waxy (inflammation). Amylose content of wheat types of inflammation ranged between 21-28% and fluffier type only 1-2%. 2) Protein. There are 4 kinds of protein in wheat seed albumin (water soluble), globulin (salt soluble), prolamin (alcohol soluble) and glutelin (alkali soluble). These proteins are located in institutions and aleurone layer, while prolamin and glutelin proteins contained in the endosperm. Grain protein content varied from 4.7 - 17%. 3) Fat. Lipid content in wheat seeds about 3.6% more than 79% of them are in institutions and less in the endosperm. Lipid content in intact seeds was 3.6% in the institution, endosperm and bran respectively 76.13% and 11%. About 80% of fat in grain form unsaturated fatty acids, especially linoleic acid and oleic 49% 31%, while the saturated fatty acids in the form of palmitic acid and stearic 14.3% 2.1%. 4). Tanin. In wheat there are 2 important pigments are carotenoids and polyphenols compounds. Polyphenol compounds consists of 4 kinds of pigments are flavonoids, antolianidine, leucoanto cianidine and tannins. Polyphenol compounds found in a layer epikarp, endokarp and Testa. Tannin content in grain ranged from 0.4 to 3.6%, and most are in the lining of Testa. Tanin able to withstand the workings of various enzymes in the digestive tract, such as trypsin, amylase, lipase and others.

Wheat flour contains very little sugar is fermented. Concentration of monosaccharides and disaccharides in wheat flour about 0.5%. It is estimated that the wheat starch and crude fiber contained approximately 65%. Starch grains mainly composed of amylose are covered by amylopectin. Wheat protein fraction is composed of 4 fractions dissolved in water, soluble in a solution of salt (NaCl), dilute, dissolve in 70% alcohol and soluble in alkali.

Wheat flour is the result of the separation of body and skin from the endosperm by milling and sifting. Particle size-zarahnya according to international standard size is 149 microns. When the number of certain powder mixed with water, it produces a certain batter. The dough can be viewed as a system of colloidal solids and water and air that eventually form a network and become sticky. The nature largely due to gluten.

In wheat flour contains less protein. Pure protein that is only composed of amino acids, that is one of organic compounds with low molecular weight. These acids covalently bind together into peptides, therefore the protein is also called polypeptides.

Classification of proteins according to Wilbraham et.al (1992) based on the solubility of proteins are classified into: 1) Albumin, this class of proteins soluble in water and aqueous solutions. Examples included in this group are ovalbumin, serum albumin, laktabumin, albumin grains, soluble in water and can be precipitated by high levels of salt solution. 2) Globulin, this class of proteins soluble in dilute salt solution, but does not dissolve in distilled water. For example ovoglobulin and serum globulin. For example ovoglobulin and serum globulin. 3) Prolamin, this group does not dissolve in water but soluble in alcohol 30-90%. Mostly found in plants such as zein in corn and wheat giladin on. 4) Glutelin, this group does not dissolve in solvents but soluble in acid or alkaline aqueous solution. This class of proteins found in plants such as in wheat and maize. Classification based on protein conformation of proteins is divided into thread or fiber (fibrous) and globular proteins.

Organic chemistry

Organic chemistry is the chemistry practice of specific disciplines to discuss the study of the structure, properties, composition, reactions, and preparation (synthesis or other sense) about bergugus chemical compounds of carbon and hydrogen, which may also comprise several other elements, including nitrogen, oxygen, the element halogen, such as phosphorus, silicon and sulfur. [1] [2] [3] The original definition of the chemical "organic" comes from the misperception of an organic mixture that is always associated with life. Not all organic compounds support life on earth entirely, but life as we know it depends also on the majority of inorganic chemistry, for example: some enzymes rely on transition metals such as iron and copper, and compound materials such as shell / skin, teeth and bone, composed mainly of organic material, some of the other inorganic. Apart from the basic material of carbon, inorganic chemistry describes only simple carbon compounds, with molecular structures which do not contain carbon to carbon chains (such as dioxide, acids, carbonates, carbides, and minerals). 

This does not mean that there is no single carbon compounds (eg methane and simple derivatives). Biochemical most elaborate protein chemistry (and larger biomolecules). Because of the nature of specific carbon chain compounds show many extreme diversity of organic compounds and a very broad application. Such compounds are basic or fundamental elements of some products (paints, plastics, food, explosives, drugs, petrochemicals, some other name) and (apart from a few exceptions) is a compound form the basis of life processes. The difference in shape and chemical reactivity of molecules specify multiple functions that surprising, such as enzyme catalysts in biochemical reactions that support life systems. Automatic breeding naturally in organic chemistry in life entirely. The trend in organic chemistry include chiral synthesis, green chemistry, microwave chemistry, fullerene (carbon alotropis) and microwave spectroscopy.