Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Cells potential

For the cell composed of a hydrogen electrode and a silver-silver chloride (Ag-AgCl) electrode immersed in a solution of HCl, represented by the notation [Pg.449]

By this convention, the potential of the cell is defined as the potential of the electrode on the right, at which reduction occurs, minus the potential of the electrode on the left, at which oxidation occurs. [Pg.449]

We know from Equation (7.84) that the free energy change of the reaction is related to the cell potential by [Pg.449]

If the pressure of hydrogen gas is maintained at the standard pressure of 1 bar, a pressure that is essentially equal to the fugacity, then the hydrogen can be considered to be in its standard state, with an activity equal to 1. As pure solid Ag and pure solid AgCl are in their standard states, their activities also are equal to 1. Thus, Equation (19.30) can be written as [Pg.450]

Both galvanic and uniform corrosion involve the concept of electromotive force or cell potential, but to understand them more thoroughly, we need to quantify the cell potential. [Pg.538]

Our observation about the relative corrosivities of various plated steels suggests that we need to express the cell potential numerically. Just how strongly is steel driven toward corrosion when connected to tin Can the tendency of a metal such as zinc to protect steel be of practical use For answers to these questions, we return to the concept of cell potential. [Pg.538]

A galvanic cell consists, as we have seen, in principle of an oxidation component in a container that draws electrons through a wire from a reduction component in another solution. The driving force causing the transfer is called the cell potential or sometimes the electromotoric force (in short EMK). The unit for cell potentials is volt (in short V) defined as joules of work coulomb charge transferred. The electromotoric force is defined as  [Pg.160]

In order for a cell reaction to take place spontaneously it is necessary that the cell potential is positive. [Pg.160]


A problem that has fascinated surface chemists is whether, through suitable measurements, one can determine absolute half-cell potentials. If some one standard half-cell potential can be determined on an absolute basis, then all others are known through the table of standard potentials. Thus, if we know E for... [Pg.210]

Note, again, that the Nernst equations for both E and Ta are written for reduction reactions. The cell potential, therefore, is... [Pg.468]

In potentiometry, the concentration of analyte in the cathodic half-cell is generally unknown, and the measured cell potential is used to determine its concentration. Thus, if the potential for the cell in Figure 11.5 is measured at -1-1.50 V, and the concentration of Zn + remains at 0.0167 M, then the concentration of Ag+ is determined by making appropriate substitutions to equation 11.3... [Pg.469]

Another problem is that the Nernst equation is a function of activities, not concentrations. As a result, cell potentials may show significant matrix effects. This problem is compounded when the analyte participates in additional equilibria. For example, the standard-state potential for the Fe "/Fe " redox couple is +0.767 V in 1 M 1TC104, H-0.70 V in 1 M ITCl, and -H0.53 in 10 M ITCl. The shift toward more negative potentials with an increasing concentration of ITCl is due to chloride s ability to form stronger complexes with Fe " than with Fe ". This problem can be minimized by replacing the standard-state potential with a matrix-dependent formal potential. Most tables of standard-state potentials also include a list of selected formal potentials (see Appendix 3D). [Pg.470]

Metallic indicator electrodes in which a metal is in contact with a solution containing its ion are called electrodes of the first kind. In general, for a metal M, in a solution of M"+, the cell potential is given as... [Pg.474]

Plot of cell potential versus the log of the analyte s concentration In the presence of a fixed concentration of Interferent, showing the determination of the selectivity coefficient. [Pg.477]

The membrane also responds to the concentration of with the cell potential given as... [Pg.479]

If a mixture of an insoluble silver salt and Ag2S is used to make the membrane, then the membrane potential also responds to the concentration of the anion of the added silver salt. Thus, pellets made from a mixture of Ag2S and AgCl can serve as a Ck ion-selective electrode, with a cell potential of... [Pg.480]

Membranes fashioned from a mixture of Ag2S with CdS, CuS, or PbS are used to make ion-selective electrodes that respond to the concentration of Cd +, Cu +, or Pb +. In this case the cell potential is... [Pg.480]

The change in the concentration of H3O+ is monitored with a pH ion-selective electrode, for which the cell potential is given by equation 11.9. The relationship between the concentration of H3O+ and CO2 is given by rearranging the equilibrium constant expression for reaction 11.10 thus... [Pg.484]

The potentiometric determination of an analyte s concentration is one of the most common quantitative analytical techniques. Perhaps the most frequently employed, routine quantitative measurement is the potentiometric determination of a solution s pH, a technique considered in more detail in the following discussion. Other areas in which potentiometric applications are important include clinical chemistry, environmental chemistry, and potentiometric titrations. Before considering these applications, however, we must first examine more closely the relationship between cell potential and the analyte s concentration, as well as methods for standardizing potentiometric measurements. [Pg.485]

Activity Versus Concentration In describing metallic and membrane indicator electrodes, the Nernst equation relates the measured cell potential to the concentration of analyte. In writing the Nernst equation, we often ignore an important detail—the... [Pg.485]

The concentration of Ca + in a water sample was determined by the method of external standards. The ionic strength of the samples and standards was maintained at a nearly constant level by making each solution 0.5 M in KNO3. The measured cell potentials for the external standards are shown in the following table. [Pg.487]

Substituting the cell potential for the sample gives the concentration of Ca + as 2.17 X 10 M. Note that the slope of the calibration curve is slightly different from the ideal value of 0.05916/2 = 0.02958. [Pg.487]

To begin, we write Nernst equations for the two measured cell potentials. The cell potential for the sample is... [Pg.488]

A second complication in measuring pH results from uncertainties in the relationship between potential and activity. For a glass membrane electrode, the cell potential, Ex, for a solution of unknown pH is given as... [Pg.491]

Equations 11.19-11.21 are defined for a potentiometric electrochemical cell in which the pH electrode is the cathode. In this case an increase in pH decreases the cell potential. Many pH meters are designed with the pH electrode as the anode so that an increase in pH increases the cell potential. The operational definition of pH then becomes... [Pg.491]

Calculate the molar concentration for the underlined component in the following cell if the cell potential is measured at +0.294 V... [Pg.535]

Group 12 (IIB) Perchlorates. The zinc perchlorate [13637-61 -17, cadmium perchlorate [13760-37-7] mercury(I) perchlorate [13932-02-0] and mercury(II) perchlorate [7616-83-3] all exist. Cell potential measurements show that zinc and cadmium perchlorates are completely dissociated in concentrations up to 0.1 molar in aqueous solutions (47—49). Mercurous perchlorate forms a tetrahydrate that can be readily converted to the dihydrate on heating to above 36°C (50). [Pg.66]

The potential of the reaction is given as = (cathodic — anodic reaction) = 0.337 — (—0.440) = +0.777 V. The positive value of the standard cell potential indicates that the reaction is spontaneous as written (see Electrochemical processing). In other words, at thermodynamic equihbrium the concentration of copper ion in the solution is very small. The standard cell potentials are, of course, only guides to be used in practice, as rarely are conditions sufftciendy controlled to be called standard. Other factors may alter the driving force of the reaction, eg, cementation using aluminum metal is usually quite anomalous. Aluminum tends to form a relatively inert oxide coating that can reduce actual cell potential. [Pg.563]

The activity coefficients of sulfuric acid have been deterrnined independentiy by measuring three types of physical phenomena cell potentials, vapor pressure, and freeting point. A consistent set of activity coefficients has been reported from 0.1 to 8 at 25°C (14), from 0.1 to 4 and 5 to 55°C (18), and from 0.001 to 0.02 m at 25°C (19). These values are all based on cell potential measurements. The activity coefficients based on vapor pressure measurements (20) agree with those from potential measurements when they are corrected to the same reference activity coefficient. [Pg.573]


See other pages where Cells potential is mentioned: [Pg.2814]    [Pg.67]    [Pg.219]    [Pg.147]    [Pg.462]    [Pg.464]    [Pg.464]    [Pg.465]    [Pg.466]    [Pg.471]    [Pg.474]    [Pg.474]    [Pg.475]    [Pg.477]    [Pg.477]    [Pg.479]    [Pg.483]    [Pg.487]    [Pg.490]    [Pg.491]    [Pg.495]    [Pg.499]    [Pg.446]    [Pg.924]    [Pg.484]    [Pg.464]    [Pg.20]    [Pg.20]    [Pg.67]    [Pg.563]   
See also in sourсe #XX -- [ Pg.43 ]




SEARCH



349 cell-potential loss

A The Effect of Current on Cell Potential

Absolute half-cell potential, determination

Action potential, cardiac cells

Action potential, cardiac cells antiarrhythmics

Action potential, cardiac cells duration

Action potential, cardiac cells prolonging

Activity coefficient determination from cell potentials

Activity determination from cell potentials

Activity from Measurement of Cell Potentials

CELL POTENTIALS UNDER STANDARD CONDITIONS

Calculation of cell potential activities or concentrations

Cardiac action potential pacemaker cells

Cardiac cells, action potential behaviors

Catalyst Work Function Variation with Potential in Solid Electrolyte Cells

Cathodic protection Cell Potential (Also Electric

Cathodic-reactant half-cell potential

Cell Potential on Concentration

Cell Potential, Electrical Work, and Free Energy

Cell Potential, Free Energy, and the Equilibrium Constant

Cell Potential-Current Dependence

Cell culture models, evaluating sensitizing potential

Cell electric potentials

Cell membrane Potential barrier

Cell membranes potentials

Cell membranes, electrical potentials across

Cell potential Electrochemical cells. Nernst equation)

Cell potential and Gibbs energy

Cell potential calculation

Cell potential changes during operation

Cell potential concentration and

Cell potential conditions

Cell potential defined

Cell potential dependence on concentration

Cell potential determination

Cell potential difference, calculation

Cell potential electrical work, and free

Cell potential electrode potentials

Cell potential energy

Cell potential equilibrium

Cell potential equilibrium constant

Cell potential force

Cell potential half-reaction potentials

Cell potential model

Cell potential nonstandard

Cell potential nonstandard conditions

Cell potential reaction free energy

Cell potential seawater

Cell potential standard reduction potentials

Cell potential standard values

Cell potential temperature dependence

Cell potential thermodynamic function

Cell potential thermodynamics

Cell potential under nonstandard

Cell potential under nonstandard conditions

Cell potential variation with

Cell potential variation with temperature

Cell potential voltaic cells

Cell potential work done

Cell potential: applications

Cell potentials Gibbs function from

Cell potentials activities

Cell potentials activity from measurement

Cell potentials measurement

Cell potentials representation

Cell potentials, their measurement

Cell voltage anode potential

Cell voltage cathode potential

Cell voltage equilibrium electrode potential

Cell wall Donnan potential

Cell wall water potential

Cells actual potential

Cells and Absolute Electrode Potentials

Cells equilibrium redox potential constant

Cells for Controlled Potential Electrolysis

Cells redox potential

Cells standard reduction potentials

Cells with a liquid junction potential

Cells with eliminated liquid junction potentials

Central-cell potential

Chemical potential from galvanic cells

Comments on the Potential of FZ Silicon for Solar Cells

Concentration cells potentials

Concentration cells, cell potential

Concentration dependence of cell potential

Concentration dependency of cell potentials

Controlled cell potential

Controlled potential electrolytic cell

Controlled-potential coulometry cell design

Controlling of the Electrochemical Reaction Rate by Electrode Potential and Cell Current

Copper half-cell potential

Corrosion thermodynamics cell potential

Dendrites, cell potential

Dependence of the Cell Potential on Concentration

Determination of Cell Potential Stability Limits by Floating

Does Mitochondrial Inhibition Mimic the Hypoxia-Induced Receptor Potential in Neonatal Chromaffin Cells

Effect of Concentration on Cell Potential

Effect of Operation Conditions on Reversible Fuel Cell Potential

Electric Potentials in the Cell

Electrical potentials across cell

Electrical potentials, Voltaic cells

Electrochemical Cells and Electrode Potentials

Electrochemical cell chemical potential

Electrochemical cell electric potential

Electrochemical cell electric potential difference generated

Electrochemical cell potential stability

Electrochemical cell standard potential

Electrochemical cells electrical potentials

Electrochemical systems half-cell potentials

Electrochemical, cells potential

Electrochemistry Cell potential Electrolysis

Electrochemistry cell potential

Electrochemistry cell potential, electrical work

Electrochemistry standard cell potential

Electrode potential and cell e.m.f. sign convention

Electrode potentials standard cell potential

Electrode potentials, Voltaic cells

Electrodeposition cell Electrode potential

Electrolytic cells nonstandard half-cell potentials

Electrostatic potential across a cell membrane

Embryonic stem cells clinical potential

Equilibrium constant from half-cell potentials

Equilibrium constant standard cell potential and

Evaluation of the Standard Cell Potential

Factors influencing cell growth potential

Free energy cell potential, electrical work

Free energy change standard cell potential and

From Measurements of Cell Potentials

Fuel cell potential-current density

Fuel cells development potential

Fuel cells potential

Galvanic cell, standard potential

Galvanic cells Batteries Cell potential

Galvanic cells cell potentials

Galvanic cells potential

Galvanic cells standard cell potential

Galvanic cells standard electrode potential

Galvanic cells standard reduction potentials

Galvanic cells, activity chemical potential

Gibbs energy and the cell potential

Gibbs energy cell potential

Gravitational cells, measurement potential

Half Cell junction potentials

Half-cell electrode potential

Half-cell potential

Half-cell potential mapping

Half-cell potential of uncoated reinforcing steel in concrete

Half-cell potential significance

Half-cell potential, definition

Half-cell potentials measurements

Half-cell potentials standard-state reduction

Half-cells redox potential

Half-cells/reactions standard reduction potentials listed

Intermolecular potentials cell theories

Linear potential sweep in thin-layer cells

Liquid junction potential, Voltaic cells

Measuring the equilibrium cell potential

Membrane potential, single cells

Membrane, biological cell potential

Metal half-cell potentials

Nerve cell Potential, spike

Nerve cell action potential

Nerve cell potential difference

Nerve cell resting potential

Nonstandard half-cell potentials

Ohmic potential drop electrochemical cell

Open cell potential line

Oxidation-reduction cell potential

Oxidation-reduction equations standard cell potential

Oxidizing agents positive reduction half-cell potentials

POTENTIALS AND THERMODYNAMICS OF CELLS

Polarized half-cell potentials

Polymer-electrolyte fuel cells electrode potential

Potential Applications of Fuel Cells

Potential Consequences of Interactions Between Aeroallergens and Cells Within the Respiratory Tree

Potential Distribution in a Hull Cell

Potential During Cell Operation

Potential and Electrochemical Cells

Potential and Voltaic Cells

Potential cell, measuring

Potential cell-density artifacts

Potential difference, electrical work done and AG for the cell reaction

Potential energy per unit cell

Potential fuel cell electrodes

Potential gradients membrane cells

Potential in nerve cells

Potential of a cell

Potential of galvanic cell

Potential of half-cell

Potential theoretical cell

Potentials and Thermodynamics of Electrochemical Cells

Potentials in a fuel cell

Potentials, in galvanic cells

Potentiation , stem cell

Prediction and significance of cell potentials

Properties from half-cell potentials

Purkinje cell action potential

Redox potential within cells

Reference electrode (half cell) potential measurements

Relating the Langmuir Constant to Cell Potential Parameters

Relationship Between Tumor Cell Trafficking and Metastatic Potential

Resting potential of cell membrane

Reversible cell potential

Reversible fuel cell potential

Reversible potential of a cell

Significance of the half-cell potential

Skill 11.5 Relating cell potentials to spontaneity and equilibrium constants

Smoothed Potential Cell Model

Solid oxide fuel cell reduction potential

Solid oxide fuel cells potential application

Spontaneous potential cells

Spontaneous potentials and electrochemical cells

Standard Cell Potential and the Equilibrium Constant

Standard Electrode (Half-Cell) Potentials at

Standard cell potential

Standard cell potential Nemst equation

Standard cell potential calculations, 246

Standard cell potential experimental determination

Standard cell potential intensive property

Standard cell potential potentials into

Standard cell potential solubility product constant

Standard cell potential, computation

Standard cell potentials definition

Standard cell potentials, variation with

Standard half-cell potentials

Standard half-cell potentials definition

Standard half-cell potentials determination

Standard half-cell potentials equilibrium constants from

Standard half-cell potentials, equilibrium

Standard potential from cells with liquid junctions

Standard reaction enthalpy from cell potential

Standard reaction entropy from cell potential

Standard reduction potentials listed for various half-cells

Standard state cell potential

Surface Charge Characteristics of Blood Cells Using Mainly Electrophoresis and to a Limited Extent Sedimentation Potential Techniques

Surface potentials, Voltaic cells

Temperature coefficient cell potential

Temperature dependence of the cell potential

The Effect of Concentration on Cell Potential

The Ionic Theory of Cell Potential by Hodgkin, Huxley, and Katz

The Nernst Equation Effect of Concentration on Half-Cell Potential

The determination of activities and activity coefficients from cell potentials

The measurement of cell potentials

Theoretical fuel cell potential

Therapeutic Potential of Adult Neural Stem Cells

Thermochemical Data Half-Cell Potentials

Todays dye-sensitized solar cells. Definition and potential

Total cell potential

Transmembrane Potential across Cell Membranes

Transmembrane electrical potential intact cell

Tumor cell trafficking, metastatic potential

Voltaic cells electrochemical potential

Voltaic cells potentials

Voltaic cells standard cell potential

Voltaic cells standard electrode potentials

Water Potential and Plant Cells

Water conductivity potential, cell

Zero-Current Electrochemical Cell Potentials—Convention

Zero-current cell potential

© 2024 chempedia.info