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Electrical work to

We now consider briefly the matter of electrode potentials. The familiar Nemst equation was at one time treated in terms of the solution pressure of the metal in the electrode, but it is better to consider directly the net chemical change accompanying the flow of 1 faraday (7 ), and to equate the electrical work to the free energy change. Thus, for the cell... [Pg.209]

The factor zF< ) arises because < ) is the electrical work to bring a unit charge, zfe0< ) is the electrical work to transport one particle bearing a charge zte(), and NAzte0 = z F[Pg.114]

Equations (8.55), (8.57) make it easy to see the connection between cell potential and reaction spontaneity. When is positive (AG < 0), the cell reaction is spontaneous, allowing useful electrical work to be withdrawn (i.e., the battery is draining ). Conversely, when is negative (AG > 0), the cell reaction is spontaneous, requiring input work from the surroundings (i.e., the battery is charging ). When = 0 (AG = 0), the cell reaction is at equilibrium, and, in accordance with (8.27d), the Nernst equation reduces to... [Pg.294]

The electrical work to place a mole of O from the solution in the OHP is ziFA1 where A02 is the potential at the OHP with respect to the potential of the solution. [Pg.35]

Ans. Not generally. For example, for carbon to form an ion to aehieve noble gas configuration, it must lose or gain four electrons. The electrical work to accomplish that is very large, and almost never available in ordinary chemical reactions. In those cases where the necessary electrical work to remove electrons from the valence shell is not available, electrons will be shared in a covalent bond. In Sec. 3.4 we will discuss a concept related to electron affinity, called electronegativity, which offers a quantitative method for deciding whether or not an ionic bond will form in the reaction between two selected elements. [Pg.59]

SECTION 20.3 A voltaic (or galvanic) cell uses a spontaneous oxidation-reduction reaction to generate electricity. In a voltaic cell the oxidation and reduction half-reactions often occur in separate halfcells. Each half-cell has a solid surface called an electrode, where the half-reaction occurs. The electrode where oxidation occurs is called the anode reduction occurs at the cathode. The electrons released at the anode flow through an external circuit (where they do electrical work) to the cathode. Electrical neutrality in the solution is maintained by the migration of ions between the two half-cells through a device such as a salt bridge. [Pg.864]

A number of devices are used in processes to transfer work between a system and its surroundings. Pumps, compressors, blowers, and fans convert shaft work into fluid energy for the main purpose of increasing fluid pressure. Turbines and expanders take energy from a fluid, causing fluid pressure to decrease, and convert the energy to shaft work for use elsewhere. A motor converts electrical work to shaft work. A generator converts shaft work to electrical work. [Pg.1073]

In actual equipment (as shown in Figure 9.61blk electrical resistance may permit only a 95% transfer of electrical work to the motor shaft, shaft friction may permit only a 90% transfer of shaft work to the fluid, and fluid friction may cause a rise in fluid temperature equivalent to a 5% loss of the shaft work. For the same increase in fluid pressure, the electrical work input to the electric motor is then... [Pg.1074]

The purpose of isolation switching is to enable electrical work to be carried out safely on an isolated circuit or piece of equipment. Isolation is intended for use by electrically skilled or supervised persons. [Pg.184]

Skilled (electrically) person - that is, a person who possesses relevent education and experience of electrical work to be able at all times to preceive risks and avoid the hazards which electricity can create. [Pg.349]

Is the electrical work to be performed in an area that contains flammable vapors, liquids, or gases, or combustible dusts or fibers ... [Pg.421]

Experiment 2 We start with the system in the same initial state as in experiment 1, and again surround it with thermal insulation. This time, instead of releasing the weight we close the switch to complete an electrical circuit with the resistor and allow the same quantity of electrical work to be done on the system as the mechanical work done in experiment 1. We discover the final temperature (300.10 K) is exactly the same as at the end of experiment 1. The process and path are different from those in experiment 1, but the work and the initial and final states are the same. [Pg.60]

Provided the work is done reversibly at constant temperature and pressure, we can equate this electrical work to the reaction Gibbs energy and obtain eqn 5.12. [Pg.196]

Negative values of E° mean that the reactions do not take place by themselves. An external source of energy needs to do electrical work to make the reaction take place. In that case, we say the reaction is taking place in an electrolytic cell instead of a galvanic cell. The difference between a cell that does electrical work and a cell that needs electrical work to be done on it is a crucial distinction. [Pg.119]

Electrical installations, whether temporary or permanent, together with electrical equipment and apparatus, should be protected by a range of measures including residual current devices (RCDs) which protect human beings from electrical shock, fuses and miniature moulded case circuit breakers (MCCBs) which provide protection to apparatus from overheating and short circuits. Arrangements should be in place to ensure that all electrical work to installations and/or electrical equipment is undertaken by only trained, qualified and competent electricians who are familiar with the systems involved. [Pg.148]

Electrical work to 415 volts 39. Storage of materials on site... [Pg.184]

Competence of all persons carrying out electrical work to be verified by inspection of current certificates of training/ experience. Training required in safe work practices (HS(G)85), and in any written safe work system, also treatment of electric shock and bums. [Pg.198]

Needle-nose pliers. These are meant for electrical work— to bend and cut wires—but you ll use them for everything from pinching tiny screws to pulling large splinters. [Pg.216]

The ratio of maximum expected voltage (E°) to thermal voltage (E°°) represents the maximum electrical work to the total available potential electrical work, the maximum thermodynamic efficiency possible ... [Pg.98]

An electrochemical cell that uses a spontaneous reaction to obtain useful work is termed a galvanic cell conversely, a cell that requires electrical work to induce a reaction that would not occur on its own is called an electrolytic cell. We can apply thermodynamics to see how much work we can obtain from a given electrochemical cell or, conversely, the minimum work that is needed to create a desired product. [Pg.590]

In this electrolytic cell, we need the input of electrical work to get the reaction to... [Pg.591]

Consider the case where all the species in the system are in their standard states. Examination of Equation (9.35) reveals that if E > 0, the reaction will spontaneously proceed. Since the half-reactions in Table 9.1 are listed in order of their numerical values, if we choose a given half-reaction as a possible reduction reaction, any oxidation half-reaction that is listed below it will result in a positive value of E xn and the reduction-oxidation couple will occur spontaneously. Conversely, any reaction listed above it will require input of electrical work to oxidize. [Pg.594]


See other pages where Electrical work to is mentioned: [Pg.256]    [Pg.93]    [Pg.115]    [Pg.222]    [Pg.93]    [Pg.222]    [Pg.226]    [Pg.54]    [Pg.135]    [Pg.64]    [Pg.341]    [Pg.198]    [Pg.253]    [Pg.977]    [Pg.97]    [Pg.19]   


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