Electrical difference

At the University of Cincinnati, Harry S. Fry was among several American chemists who began using directional or arrow formulas. Another was Julius Stieglitz at the University of Chicago. Fry invented the word "electromers" for electrically different isomers and "electronic tautomerism" for nonisolable tautomers in dynamic equilibrium with each other. He applied the latter idea to benzene, arguing that benzene exists as six electromers in equilibrium with... 

Potassium channels are part of a complex system that helps maintain the normal ionic balance across the cell membrane. In excitable cells, like those in nerves and muscles, the channels also help reestablish the electrical difference between the inside and outside of the cells after excitation. In the case of neuron firing, potassium ions, and thus positive charge, builds up inside the... 

Another approach for separation is to adjust chromatographic conditions to maximise chemical or apparent molecular size differences of dissolved components. Then, electrically different groups can be fractionated by size exclusion stationary phases even... 

Biomass can be converted to different energy products, such as heat and electricity, different transport fuels, such as methanol, DME and other chemicals by thermochemical processes. These thermochemical processes can be divided into several main groups ... 

The diffusion of charged ions is more complicated because of the law of electroneutrality, which states that the sum of the positive charges on each side of the membrane must equal the sum of the negative charges. In addition to the concentration gradient, the electrical potential difference determines the Bnal equilibrium of a substance across the membrane. Therefore at equilibrium, the concentration of an ionic species may be unequal across the membrane and this gradient will balance the electrical difference across the membrane. The driving force for transport in this situation is defined as the electrochemical potential. The Nemst equation describes the equilibrium situation for ions... 

The same principle may naturally be expected to display itself with regard to acids and bases. The oxygen of an acid unites itself to the (electrically ) different oxygen of water. The oxygen of a base on the same principle has an affinity for the electrically different oxygen of water. 

The processes that use energy from changes in potential or from energetically favorable chemical processes are called active transport processes. They can move substances against a concentration gradient using the additional contribution from AG which is not available in diffusion-driven processes. Students should be aware that both of these mechanisms can also be used to oppose transfer as well. Hence, electrical differences across a membrane may oppose a transfer instead of favor it and formation of ATP from ADP + Pi may be too energetically unfavorable of a barrier to allow a transfer to occur. 

Carbon surfaces hold a charge density that arises fiom electron imbalances due to the incomplete coordination of their outermost atoms. In order to minimize the electrical difference between the surface and the bulk of the solid, the charge held is balanced by the redistribution of surrounding ions, resulting in electrostatic interactions between the ions/molecules in solution and the carbon surface. The result is diat the attracted ions approach the carbon sur ce, as predicted tty Coulomb s law, creating a drop in the electric potential which is confined to a limited region in solution (termed die outer Helmholtz Plane) and fonn the so-called electrical double layer (EDL). 

The capacities of these demonstration power plants are very small by utility standards. To examine the economy-of-scale effect of Energy Plantation-produced electricity, different-sized "high-performance" power plants were analyzed at one location where an intermediate electricity cost prevails, viz., Natchitoches. Louisiana. The load factor used in these calculations was 33 percent. The results are shown in Figure II. These costs show a marked economy-of-scale effect, with "utility-method" costs dropping from 43 to 32 mills/kWhr over the same range of generator capacities. 

Is it not very improbable, asks Hartley that two kinds of micelles, which exhibit exclusively electrical differences, occur in the same soap solution In fact an attempt originated with this author to explain all the phenomena with the aid... 

Volta gave a plate of 21 diagrams of different combinations of conductors of the first and second classes and shows in detail how each would behave on the basis of his law or principle. With tin alone, between water and an alkaline liquid (as in the experiment described) almost the same action is obtained as with the most electrically different metals (silver and zinc) with an aqueous conductor between them, and it may be equalled or even exceeded with iron alone between water and nitric acid, or silver alone between water and liquid alkali sulphide ( 23). Volta made experiments with conducting bridges formed between cups of liquids by moist leather or card, a piece of juicy flesh, a sinew or gristle, or a slice of cucumber or melon, or anything which allows an electric current (corrente elettrica) to pass ( 29). 

From (i) and (2), if the electric difference between zinc and copper is represented by the number 4-17, then the difference between zinc and zinc vitriol is 5 21 and that between copper and copper vitriol is 0 70, But 5 21 0 70 =4 51, and Fobs. =4-51. 

L. Schmid, with an apparatus like Wild s, found that solutions of alkali-metal chlorides and nitrates obey Volta s law. Solutions of sulphates, nitrates, and chlorides of silver and bivalent metals followed the potential series of the metals. This was used to find the order of several metals in the potential series. Schmid concluded that the electrical difference of two different salts of the same metal is equal to the electrical difference of the acids. He also used solid salts pressed into discs which were brought in contact. 

Linus Pauling, an American chemist, was the first to take a closer look at the electrical difference of bonds. He tested the differences in energies of covalent bonds. In 1939, he published The Nature of the Chemical Bond which discussed the energy levels of molecules. Pauling was recognized for his work with protein structures. His electrochemical valency theory won the Nobel Prize for Chemistry in 1954. 

Which American chemist first described the electrical difference of bonds ... 

The potential difference between the electrodes can be treated as the work done to move the charge from the positive electrode to the negative electrode. Similar to Equation (1.5), the work or electric difference between two electrodes (AV) can be expressed as... 

The electric difference between the two electrodes of a capacitor can be alternatively expressed as V rather than AV ... 

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