The reactivity of a bond or an atom towards a particular reagent in a compound is significantly affected by the availability of electrons. The influence availability of electron density is affected by following factors: inductive effect, mesomeric effect, electromeric effect and hyperconjugation.
Inductive Effect
In chemical makeup and science, the 'Inductive Effect' is an experimentally observable impact of the transmitting of charge through a chain of atoms in a molecule. It can also define as the process of electron displacement along the chain of carbon atoms.
It is a permanent effect and results due to the presence of a polar covalent bond at one end of the chain and does not depend upon the presence of a reagent. Electrons displaced towards more electronegative atom.
When atom or group of atoms have greater electron attracting capacity than hydrogen this is the electron-withdrawing inductive effect, also known as the -I effect. The positive charge is relayed to the other atoms in the chain, if the electronegative atom joined a chain of carbon atoms. Example of electron-withdrawing inductive effect (-I) effect
• NO2> CN>COOH>F>Cl> Br> I > OH> OCH3 > C6H5 > H
When atoms or group of atoms having smaller electron attracting power than hydrogen, they repel electrons towards carbon atom this is the electron-repelling inductive effect, also known as the +I effect. Example of electron- repelling inductive effect (+I) effect.
• (CH3)3C > (CH3)2CH > CH3CH2 > CH3
The more electronegative atom has a slight negative charge (δ–) and the other atom has a slight positive charge (δ+). In able to decide the point of attack in molecule, inductive affects changes the electron density in a molecule.
Mesomeric effect
The mesomeric effect...
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...entiating in bond length, resonance affects the bond length: single bond is shortened while the double bond becomes longer while, tautomerism has no effect on bond length.
About the dynamic equilibrium resonating structures are not in dynamic equilibrium but tautomerism is in dynamic equilibrium with each other. The two tautomeric forms exist together though the equilibrium may shift to either side with a change in condition. The tautomers have a physical reality whereas the resonance structures are imaginary.
Change in the position of atom (generally hydrogen) involve in tautomerism, while resonance involve a change in the position of the unshared or pi bond only. Example, by considering an amide which is 1.52 the resonance form 1.53 shows a different in the position of charge, while the tautomer 1.54 shows a different in the position of a hydrogen atom.
a) The excitation of electrons of both metal ion and ligand is influenced by their interactions.
Therefore any changes in the cell are ascribable to the working electrode. The control of potential of working electrode with respect to reference electrode is equivalent of the controlling of energy of electrons within the working electrode. As shown in Fig. 1.3, scanning the potential in the negative direction makes the electrode a stronger reductant, whereas scanning the potential in the positive direction makes it a better
tension of the system. Their orientation at the interface varies, depending on the components of
...ibrium shares the same definition as chemical equilibrium. They both occur whenever the rates of the forward and reverse reactions are equal to each other. The common ion effect is the idea that if a reaction ever falls out of equilibrium, a shift will occur to re-balance it again. The addition of a common ion to the weak side of an equilibrium will result in a shift towards the right side of the reaction, which are the reactants and the weak parts of the equilibrium. [5]
The pitch of a vibrating string depends on mass of the string, tension and the length of the string: strings with more mass vibrate more slowly. On steel string guitars, the strings get thicker from high to low. Tension is varied by using the tuning pegs: tighter gives higher pitch. Similarly, shorter string gives higher pitch. The sound produced by the string is faint which is then amplified by it...
...Coauthor, ChemBioChem 2006, 7, 1-10; b) A. Author, B. Coauthor, Angew. Chem. 2006, 118, 1-5; Angew. Chem. Int. Ed. 2006, 45, 1-5.))
The electrophile is positively charged, so it will not go to the ortho and para positions, but to the meta positions in greater abundance. Therefore, the majority of EWGs (with the exception of halogens) are meta directors. In this experiment, a meta director is used. If the product added to the ortho or para positions produces a carbocation intermediate that has a positive charge on a carbon that is directly touching the EWG. This carbocation intermediate has more energy, and is therefore less stable.
An elements¡¦ reaction to certain substances may be predicted by its placement on the Periodic Table of Elements. Across a period, an element on the left will react with more vigor than one on the right, of the same period. Vertically, as elements are sectioned into groups, the reaction of each element increases as you move down in the same group. With this in mind, the reactions of the substances involved in this experiment may be hypothesized, observed, and validated.
The Effect of the Number of Coils on an Electromagnet On Its Strength Aim: - To establish whether a variation in the number of coils will affect an electromagnet's strength. Scientific Knowledge -. The concept of electromagnets is fairly simple. An iron nail wrapped in a series of coils of insulated wire and then connected to a battery, will enable the nail to pick up paper clips. This is because the current emitted from the battery to the coils magnetizes the nail to the surface.
The effects of electric force can be summarized as the law of electric charge: Pieces of matter with the same kind of charge repel each other. Pieces of matter with the same kind of charge attract each other. 2 objects with a positive charge repel each other, as do 2 objects with a negative charge.
First off, what is current. Current is expressed in a unit called Amps. Amps are a measurement of how many electrons pass per second. That is to say, a wire with 40 coulombs passing any point in a 2 seconds would be said to have 20 Amps of current (40 Coulombs (a unit of charge given as 6.24x1018 electrons) / time in seconds or in this case, 2 seconds. The Amp is also known as Coulombs per second) Another trick about current is that it is measured in the movement of the positive charge. Literally that is to say the current moves in oppostion to the electrons. This is because originally it was thought that the positive charge is what moved, both are viable, but in reality a positive charge is generally fixed since within an atom the electrons are migratory, while the protons and neutrons tend to be stationary.
the more time it will take for the particles to react. This is due to
Electrophoresis is the migration of a charged molecule under the influence of an electric field . The electrophoretic mobility is given by :
neutralized by the base. The point was signaled by a changing of color of an