Coulometry and electrogravimetric analysis are analytical techniques that involve completely oxidizing or reducing an analyte through electrolysis. In coulometry, the quantity of electrical charge passed is measured and related to the amount of analyte present. In electrogravimetry, the analyte is converted electrolytically into a product that is weighed to determine the analyte amount. Both techniques are accurate and precise, but require ensuring all current passed results in analyte oxidation/reduction. Controlled-potential coulometry uses a constant potential, while controlled-current coulometry applies a constant current, each with their own experimental considerations to achieve complete analyte conversion.
This document discusses cyclic voltammetry, which is a type of potentiodynamic electrochemical measurement where the current in an electrochemical cell is measured while the cell's potential is varied linearly with time. It describes the components of a voltammetry system, including the working, reference, and counter electrodes, as well as the supporting electrolyte. It also explains the triangular potential waveform used and defines terms like peak current and peak potential. Examples of using cyclic voltammetry to study the redox reaction of hexacyanoferrate ions and biological redox systems like cytochromes are provided.
This document provides an overview of coulometry, which is an electroanalytical technique used for quantitative analysis. There are two forms of coulometry: controlled-potential coulometry and controlled-current coulometry. Both techniques involve completely oxidizing or reducing an analyte and measuring the total charge passed to determine the amount of analyte. Controlled-potential coulometry applies a constant potential while controlled-current coulometry applies a constant current. Factors like electrolysis time, electrode area, and stirring rate affect the analysis. Coulometry is used to quantify both inorganic and organic analytes.
Voltammetry involves applying a potential to a working electrode and measuring the resulting current. It can characterize redox reactions through parameters like peak potentials and currents in cyclic voltammetry. Cyclic voltammetry cycles the potential of a working electrode versus a reference electrode and measures the current. It is used to study redox processes and obtain information about reaction kinetics and mechanisms. The peak separation and shapes of cyclic voltammograms provide information about whether redox processes are reversible or irreversible.
This document discusses electrogravimetry, which is the quantitative analysis of substances by electrolysis. It defines key terms used in electrogravimetry like cathode, anode, current density, and overpotential. It explains Faraday's laws of electrolysis and how they relate to the amount of material deposited. It also describes how controlling variables like cathode potential can be used to selectively deposit metals and separate them from each other.
Coulometry is an electroanalytical technique where the amount of electricity (in coulombs) required to complete an electrochemical reaction is measured. There are two main types - potentiostatic coulometry, where the potential is held constant, and coulometric titration with a constant current. The quantity of electricity is directly proportional to the amount of analyte and can be used to determine concentrations. Coulometry has applications in inorganic analysis, analysis of radioactive materials, microanalysis, and determination of organic compounds.
Electrogravimetric analysis involves the quantitative deposition of an analyte onto an electrode through electrolysis. There are two main types: constant current electrolysis, where the current is kept constant and the potential varies, and controlled potential electrolysis, where the potential is kept constant to selectively deposit analytes. Electrogravimetric analysis can be used for quantitative analysis, separation, preconcentration of analytes, and electrosynthesis.
Coulometry is an electroanalytical technique that measures the quantity of electricity required for a chemical reaction. There are two main types - controlled potential coulometry (potentiostatic coulometry) and controlled current coulometry (galvanostatic coulometry). Controlled potential coulometry involves holding the working electrode at a constant potential to allow exhaustive electrolysis of the analyte without interfering reactions. The quantity of electricity passed is proportional to the analyte concentration and is measured with an electronic integrator. Applications include determination of metal ions, microanalysis, and analysis of radioactive materials like uranium.
This document discusses cyclic voltammetry, which is a type of potentiodynamic electrochemical measurement where the current in an electrochemical cell is measured while the cell's potential is varied linearly with time. It describes the components of a voltammetry system, including the working, reference, and counter electrodes, as well as the supporting electrolyte. It also explains the triangular potential waveform used and defines terms like peak current and peak potential. Examples of using cyclic voltammetry to study the redox reaction of hexacyanoferrate ions and biological redox systems like cytochromes are provided.
This document provides an overview of coulometry, which is an electroanalytical technique used for quantitative analysis. There are two forms of coulometry: controlled-potential coulometry and controlled-current coulometry. Both techniques involve completely oxidizing or reducing an analyte and measuring the total charge passed to determine the amount of analyte. Controlled-potential coulometry applies a constant potential while controlled-current coulometry applies a constant current. Factors like electrolysis time, electrode area, and stirring rate affect the analysis. Coulometry is used to quantify both inorganic and organic analytes.
Voltammetry involves applying a potential to a working electrode and measuring the resulting current. It can characterize redox reactions through parameters like peak potentials and currents in cyclic voltammetry. Cyclic voltammetry cycles the potential of a working electrode versus a reference electrode and measures the current. It is used to study redox processes and obtain information about reaction kinetics and mechanisms. The peak separation and shapes of cyclic voltammograms provide information about whether redox processes are reversible or irreversible.
This document discusses electrogravimetry, which is the quantitative analysis of substances by electrolysis. It defines key terms used in electrogravimetry like cathode, anode, current density, and overpotential. It explains Faraday's laws of electrolysis and how they relate to the amount of material deposited. It also describes how controlling variables like cathode potential can be used to selectively deposit metals and separate them from each other.
Coulometry is an electroanalytical technique where the amount of electricity (in coulombs) required to complete an electrochemical reaction is measured. There are two main types - potentiostatic coulometry, where the potential is held constant, and coulometric titration with a constant current. The quantity of electricity is directly proportional to the amount of analyte and can be used to determine concentrations. Coulometry has applications in inorganic analysis, analysis of radioactive materials, microanalysis, and determination of organic compounds.
Electrogravimetric analysis involves the quantitative deposition of an analyte onto an electrode through electrolysis. There are two main types: constant current electrolysis, where the current is kept constant and the potential varies, and controlled potential electrolysis, where the potential is kept constant to selectively deposit analytes. Electrogravimetric analysis can be used for quantitative analysis, separation, preconcentration of analytes, and electrosynthesis.
Coulometry is an electroanalytical technique that measures the quantity of electricity required for a chemical reaction. There are two main types - controlled potential coulometry (potentiostatic coulometry) and controlled current coulometry (galvanostatic coulometry). Controlled potential coulometry involves holding the working electrode at a constant potential to allow exhaustive electrolysis of the analyte without interfering reactions. The quantity of electricity passed is proportional to the analyte concentration and is measured with an electronic integrator. Applications include determination of metal ions, microanalysis, and analysis of radioactive materials like uranium.
The document provides information about electroanalytical methods of analysis. It defines electroanalytical methods as techniques that study analytes by measuring potentials or currents in an electrochemical cell containing the analyte. It discusses various types of electroanalytical techniques including potentiometry, voltammetry, and Karl Fischer titration. It provides details on the principles, instrumentation, applications, and advantages of these analytical methods.
Electrochemistry 1 the basic of the basicToru Hara
This document discusses key concepts in electrochemistry including the interface between electrode and electrolyte, thermodynamics and kinetics of electrode reactions, and overpotential. The interface contains an electric double layer consisting of an inner monomolecular layer, an outer diffuse region, and an intermediate layer. Overpotential arises from factors like activation energy needed for electrode reactions, concentration gradients that develop at the electrode surface, and resistance of the electrolyte. Overpotential is composed of ohmic drop, activation overpotential, and diffusion overpotential.
Cyclic voltammetry is an electroanalytical technique that measures current during redox reactions at an electrode. It involves scanning the potential of a working electrode versus a reference electrode and measuring the current. The potential is ramped from an initial value to a set switching potential and back to the initial value. This process is repeated in cycles. A cyclic voltammogram plots the current response of the working electrode versus the applied potential and provides information about redox potentials and reaction reversibility. Reversible reactions produce symmetrical peaks while irreversible reactions have wider separation between peaks. Cyclic voltammetry is useful for studying electrode reaction mechanisms and kinetics.
lecture slide on:
Gibbs free energy and Nernst Equation, Faradaic Processes and Factors Affecting Rates of Electrode Reactions, Potentials and Thermodynamics of Cells, Kinetics of Electrode Reactions, Kinetic controlled reactions,Essentials of Electrode Reactions,BUTLER-VOLMER MODEL FOR THE ONE-STEP, ONE-ELECTRON PROCESS,Current-overpotential curves for the system, Mass Transfer by Migration And Diffusion,MASS-TRANSFER-CONTROLLED REACTIONS,
This document discusses various electroanalytical techniques. It begins by introducing electroanalytical techniques and their objectives. It then describes different types of techniques including coulometry, amperometry, voltammetry, polarography, potentiometry, conductometry, and others. It also discusses electrochemical cells, potentials in electroanalytical cells using the Nernst equation, and mass transfer processes like migration, convection, and diffusion.
This document presents information on the Tanabe-Sugano diagram, which is used in coordination chemistry to predict absorptions in the UV-visible and IR spectra of coordination compounds. It was developed by Yukito Tanabe and Satoru Sugano in 1954 to explain the absorption spectra of octahedral complex ions. The diagram plots orbital energy as a function of the Racah parameter B versus the ligand field splitting parameter Δo/B. It can be used to determine the ordering of electronic states and predict possible electronic transitions based on parameters like Δo, Racah parameters B and C, symmetry rules, and term symbols of electronic configurations. The diagram has advantages over earlier Orgel diagrams in that it can be applied to
Dc,pulse,ac and square wave polarographic techniques newBiji Saro
DC, pulse, AC, and square wave polarographic techniques are electroanalytical methods used to determine the concentration and nature of electroactive species in solutions. DC polarography applies a continuously increasing voltage to generate a sigmoidal current-voltage curve. Pulse polarography applies voltage pulses to eliminate non-faradaic currents and improve detection limits. AC polarography superimposes an AC potential on DC to measure the AC current component. Square wave polarography uses large amplitude square waves to sample current twice per cycle and plot the net current versus voltage. These techniques enable sensitive quantitative analysis down to micromolar and even nanomolar concentration levels.
This document discusses ligand substitution reactions in octahedral complexes. It describes the main mechanisms of ligand substitution including dissociative (SN1), associative (SN2), and concerted (interchange) pathways. It also discusses hydrolysis reactions and anation reactions as types of ligand substitutions. Specific examples are provided of acid and base hydrolysis in octahedral cobalt complexes, and factors that influence the reaction mechanisms and rates are outlined.
Voltammetry is a technique where a time-dependent potential is applied to an electrochemical cell and the current is measured as a function of the applied potential. This results in a voltammogram which provides qualitative and quantitative information about redox reactions. The earliest technique was polarography developed in the 1920s. Modern voltammetry uses a three-electrode system with various excitation signals applied. Common techniques include normal pulse polarography, differential pulse polarography, staircase polarography and square wave polarography which have better sensitivity than normal polarography. The shape of the voltammetric wave depends on factors like the reversibility of the redox reaction. The diffusion current occurs at very negative potentials where the reaction rate is controlled by diffusion
This document discusses electronic spectra of metal complexes. It begins by defining quantum numbers related to electron configuration, such as L (total orbital angular momentum) and l (secondary quantum number). It then describes two main types of electronic transitions in coordination compounds: d-d transitions specific to metals, and charge-transfer transitions. The remainder of the document discusses charge-transfer transitions in more detail, defining ligand-to-metal and metal-to-ligand charge transfer, and how solvent polarity affects these transitions.
This document discusses polarography, which is a technique for analyzing solutions using two electrodes - a dropping mercury working electrode and a reference electrode. It provides details on:
1. How polarography works by applying a voltage to induce a redox reaction and measuring the resulting current.
2. The components needed, including the dropping mercury electrode, reference electrode, and a supporting electrolyte.
3. How polarograms are generated by plotting current vs. applied voltage and the different regions that can be seen on a polarogram.
4. Factors that influence the diffusion current measured, such as concentration of the analyte, diffusion coefficient, and drop lifetime. Equations for calculating diffusion current are also presented.
Cyclic voltammetry is an electroanalytical technique that measures the current in an electrochemical cell containing a working electrode, reference electrode, and counter electrode. During cyclic voltammetry, the potential of the working electrode is scanned linearly versus time. This produces a current that is plotted against the potential to give a cyclic voltammogram. Cyclic voltammetry provides information about redox reactions and reaction mechanisms through features like peak currents and separations in the voltammogram. It can be used to determine properties like the number of electrons transferred in a reaction, surface coverage, and diffusion coefficients.
This document discusses applications of cyclic voltammetry (CV). CV is an electrochemical technique useful for studying electrode reactions. It involves applying a continuous, cyclic potential to a working electrode in a cell containing three electrodes. The document outlines the principle, working, and applications of CV, including quantitative analysis, studying chemical reactivity and redox processes, determining thermodynamic properties, kinetics, and more. Examples are given of using CV to characterize modified electrodes and study interactions like of anticancer drugs with DNA.
It contains the basic principle of Mossbauer Spectroscopy.
Recoil energy, Dopler shift.
The instrumentation of Mossbauer Spectroscopy.
Hyperfine interactions.
Electronic spectra of metal complexes-1SANTHANAM V
This document discusses electronic spectra of metal complexes. It begins by relating the observed color of complexes to the light absorbed and corresponding wavelength ranges. It then discusses the use of electronic spectra to determine d-d transition energies and the factors that affect d orbital energies. Key terms like states, microstates, and quantum numbers are introduced. Configuration, inter-electronic repulsions described by Racah parameters, nephelauxetic effect, and spin-orbit coupling are explained as factors that determine the splitting of energy levels. Russell-Saunders and j-j coupling are outlined as approaches to describe spin-orbit interactions in light and heavy elements respectively.
Electrogravimetry is a method used to separate and quantify ions of a substance, usually a metal, through electrolysis. The analyte solution is electrolyzed, causing the analyte to deposit on the cathode. The cathode is weighed before and after the experiment, and the mass difference is used to calculate the amount of analyte originally present. There are two types of electrogravimetry - constant current electrolysis, where the current is kept constant, and constant potential electrolysis, where the potential is kept constant. In both cases, the deposited analyte on the cathode is measured through changes in mass to determine the concentration in the original solution.
This document discusses electrolytic solutions and electrochemistry. It begins by defining electrochemistry as the study of chemical reactions involving electron transfer between an electrode and electrolyte. It then discusses different types of solutions, distinguishing between electrolytic and non-electrolytic solutions. Electrolytic solutions contain ions and are electrically conductive. The document also discusses the differences between electronic and electrolytic conductors, and how conductivity is affected by various factors like temperature, concentration, and ion size. It introduces concepts like equivalent conductance, molar conductance, activity, and activity coefficients. In summary, the document provides an overview of key concepts relating to electrolytic solutions and electrochemistry.
Coulometry is an electrochemical method that measures the current needed to completely oxidize or reduce an analyte. There are two forms: controlled potential and controlled current. Controlled potential coulometry applies a constant potential to ensure 100% current efficiency and quantitative reaction of the analyte without interfering species. The decreasing current over time corresponds to decreasing analyte concentration. Controlled current coulometry passes a constant current, allowing more rapid analysis since current does not decrease over time. The total charge simply equals current multiplied by time. Coulometry provides precise, sensitive, and selective analysis of inorganic and organic compounds and can be adapted to automatic titration methods.
Improvement of the electric power quality usingVikram Rawani
A control algorithm for a three-phase hybrid power
filter is proposed.It is constituted by a series active filter and a passive filter connected in parallel with the load.
The document provides information about electroanalytical methods of analysis. It defines electroanalytical methods as techniques that study analytes by measuring potentials or currents in an electrochemical cell containing the analyte. It discusses various types of electroanalytical techniques including potentiometry, voltammetry, and Karl Fischer titration. It provides details on the principles, instrumentation, applications, and advantages of these analytical methods.
Electrochemistry 1 the basic of the basicToru Hara
This document discusses key concepts in electrochemistry including the interface between electrode and electrolyte, thermodynamics and kinetics of electrode reactions, and overpotential. The interface contains an electric double layer consisting of an inner monomolecular layer, an outer diffuse region, and an intermediate layer. Overpotential arises from factors like activation energy needed for electrode reactions, concentration gradients that develop at the electrode surface, and resistance of the electrolyte. Overpotential is composed of ohmic drop, activation overpotential, and diffusion overpotential.
Cyclic voltammetry is an electroanalytical technique that measures current during redox reactions at an electrode. It involves scanning the potential of a working electrode versus a reference electrode and measuring the current. The potential is ramped from an initial value to a set switching potential and back to the initial value. This process is repeated in cycles. A cyclic voltammogram plots the current response of the working electrode versus the applied potential and provides information about redox potentials and reaction reversibility. Reversible reactions produce symmetrical peaks while irreversible reactions have wider separation between peaks. Cyclic voltammetry is useful for studying electrode reaction mechanisms and kinetics.
lecture slide on:
Gibbs free energy and Nernst Equation, Faradaic Processes and Factors Affecting Rates of Electrode Reactions, Potentials and Thermodynamics of Cells, Kinetics of Electrode Reactions, Kinetic controlled reactions,Essentials of Electrode Reactions,BUTLER-VOLMER MODEL FOR THE ONE-STEP, ONE-ELECTRON PROCESS,Current-overpotential curves for the system, Mass Transfer by Migration And Diffusion,MASS-TRANSFER-CONTROLLED REACTIONS,
This document discusses various electroanalytical techniques. It begins by introducing electroanalytical techniques and their objectives. It then describes different types of techniques including coulometry, amperometry, voltammetry, polarography, potentiometry, conductometry, and others. It also discusses electrochemical cells, potentials in electroanalytical cells using the Nernst equation, and mass transfer processes like migration, convection, and diffusion.
This document presents information on the Tanabe-Sugano diagram, which is used in coordination chemistry to predict absorptions in the UV-visible and IR spectra of coordination compounds. It was developed by Yukito Tanabe and Satoru Sugano in 1954 to explain the absorption spectra of octahedral complex ions. The diagram plots orbital energy as a function of the Racah parameter B versus the ligand field splitting parameter Δo/B. It can be used to determine the ordering of electronic states and predict possible electronic transitions based on parameters like Δo, Racah parameters B and C, symmetry rules, and term symbols of electronic configurations. The diagram has advantages over earlier Orgel diagrams in that it can be applied to
Dc,pulse,ac and square wave polarographic techniques newBiji Saro
DC, pulse, AC, and square wave polarographic techniques are electroanalytical methods used to determine the concentration and nature of electroactive species in solutions. DC polarography applies a continuously increasing voltage to generate a sigmoidal current-voltage curve. Pulse polarography applies voltage pulses to eliminate non-faradaic currents and improve detection limits. AC polarography superimposes an AC potential on DC to measure the AC current component. Square wave polarography uses large amplitude square waves to sample current twice per cycle and plot the net current versus voltage. These techniques enable sensitive quantitative analysis down to micromolar and even nanomolar concentration levels.
This document discusses ligand substitution reactions in octahedral complexes. It describes the main mechanisms of ligand substitution including dissociative (SN1), associative (SN2), and concerted (interchange) pathways. It also discusses hydrolysis reactions and anation reactions as types of ligand substitutions. Specific examples are provided of acid and base hydrolysis in octahedral cobalt complexes, and factors that influence the reaction mechanisms and rates are outlined.
Voltammetry is a technique where a time-dependent potential is applied to an electrochemical cell and the current is measured as a function of the applied potential. This results in a voltammogram which provides qualitative and quantitative information about redox reactions. The earliest technique was polarography developed in the 1920s. Modern voltammetry uses a three-electrode system with various excitation signals applied. Common techniques include normal pulse polarography, differential pulse polarography, staircase polarography and square wave polarography which have better sensitivity than normal polarography. The shape of the voltammetric wave depends on factors like the reversibility of the redox reaction. The diffusion current occurs at very negative potentials where the reaction rate is controlled by diffusion
This document discusses electronic spectra of metal complexes. It begins by defining quantum numbers related to electron configuration, such as L (total orbital angular momentum) and l (secondary quantum number). It then describes two main types of electronic transitions in coordination compounds: d-d transitions specific to metals, and charge-transfer transitions. The remainder of the document discusses charge-transfer transitions in more detail, defining ligand-to-metal and metal-to-ligand charge transfer, and how solvent polarity affects these transitions.
This document discusses polarography, which is a technique for analyzing solutions using two electrodes - a dropping mercury working electrode and a reference electrode. It provides details on:
1. How polarography works by applying a voltage to induce a redox reaction and measuring the resulting current.
2. The components needed, including the dropping mercury electrode, reference electrode, and a supporting electrolyte.
3. How polarograms are generated by plotting current vs. applied voltage and the different regions that can be seen on a polarogram.
4. Factors that influence the diffusion current measured, such as concentration of the analyte, diffusion coefficient, and drop lifetime. Equations for calculating diffusion current are also presented.
Cyclic voltammetry is an electroanalytical technique that measures the current in an electrochemical cell containing a working electrode, reference electrode, and counter electrode. During cyclic voltammetry, the potential of the working electrode is scanned linearly versus time. This produces a current that is plotted against the potential to give a cyclic voltammogram. Cyclic voltammetry provides information about redox reactions and reaction mechanisms through features like peak currents and separations in the voltammogram. It can be used to determine properties like the number of electrons transferred in a reaction, surface coverage, and diffusion coefficients.
This document discusses applications of cyclic voltammetry (CV). CV is an electrochemical technique useful for studying electrode reactions. It involves applying a continuous, cyclic potential to a working electrode in a cell containing three electrodes. The document outlines the principle, working, and applications of CV, including quantitative analysis, studying chemical reactivity and redox processes, determining thermodynamic properties, kinetics, and more. Examples are given of using CV to characterize modified electrodes and study interactions like of anticancer drugs with DNA.
It contains the basic principle of Mossbauer Spectroscopy.
Recoil energy, Dopler shift.
The instrumentation of Mossbauer Spectroscopy.
Hyperfine interactions.
Electronic spectra of metal complexes-1SANTHANAM V
This document discusses electronic spectra of metal complexes. It begins by relating the observed color of complexes to the light absorbed and corresponding wavelength ranges. It then discusses the use of electronic spectra to determine d-d transition energies and the factors that affect d orbital energies. Key terms like states, microstates, and quantum numbers are introduced. Configuration, inter-electronic repulsions described by Racah parameters, nephelauxetic effect, and spin-orbit coupling are explained as factors that determine the splitting of energy levels. Russell-Saunders and j-j coupling are outlined as approaches to describe spin-orbit interactions in light and heavy elements respectively.
Electrogravimetry is a method used to separate and quantify ions of a substance, usually a metal, through electrolysis. The analyte solution is electrolyzed, causing the analyte to deposit on the cathode. The cathode is weighed before and after the experiment, and the mass difference is used to calculate the amount of analyte originally present. There are two types of electrogravimetry - constant current electrolysis, where the current is kept constant, and constant potential electrolysis, where the potential is kept constant. In both cases, the deposited analyte on the cathode is measured through changes in mass to determine the concentration in the original solution.
This document discusses electrolytic solutions and electrochemistry. It begins by defining electrochemistry as the study of chemical reactions involving electron transfer between an electrode and electrolyte. It then discusses different types of solutions, distinguishing between electrolytic and non-electrolytic solutions. Electrolytic solutions contain ions and are electrically conductive. The document also discusses the differences between electronic and electrolytic conductors, and how conductivity is affected by various factors like temperature, concentration, and ion size. It introduces concepts like equivalent conductance, molar conductance, activity, and activity coefficients. In summary, the document provides an overview of key concepts relating to electrolytic solutions and electrochemistry.
Coulometry is an electrochemical method that measures the current needed to completely oxidize or reduce an analyte. There are two forms: controlled potential and controlled current. Controlled potential coulometry applies a constant potential to ensure 100% current efficiency and quantitative reaction of the analyte without interfering species. The decreasing current over time corresponds to decreasing analyte concentration. Controlled current coulometry passes a constant current, allowing more rapid analysis since current does not decrease over time. The total charge simply equals current multiplied by time. Coulometry provides precise, sensitive, and selective analysis of inorganic and organic compounds and can be adapted to automatic titration methods.
Improvement of the electric power quality usingVikram Rawani
A control algorithm for a three-phase hybrid power
filter is proposed.It is constituted by a series active filter and a passive filter connected in parallel with the load.
This document summarizes a paper on renewable energy sources with a flyback converter for DC applications. It discusses using a solar panel and fuel cell as renewable energy sources to provide input power to a three-level phase-shift forward flyback converter. It models the photovoltaic array and fuel cell to simulate their output. It then describes the operating principle and key waveforms of the proposed flyback converter. Simulation results show the output voltage from the solar panel, input voltage to the converter, and speed of a DC motor driven by the converter. The study demonstrates using solar and fuel cell sources with a flyback converter to provide stable power for DC applications like motor drives.
This document summarizes a study that optimized hydrogen production from a photovoltaic-electrolysis system. A proton exchange membrane electrolysis was connected to a photovoltaic array via a DC/DC buck converter with maximum power point tracking control. This allowed maximization of power transfer to the electrolysis and control of injected water flow. Simulation results showed that controlling water flow based on power variations from weather changes and using the DC/DC converter with MPPT control allowed for better adaptation between the PV array and electrolysis, leading to optimal system functioning and maximum hydrogen production.
Quantitative Modeling and Simulation of Single-Electron TransistorIRJET Journal
This document discusses quantitative modeling and simulation of the single-electron transistor (SET) using MATLAB Simulink. The SET is a nano-scaled transistor that operates using quantum tunneling of single electrons. The document describes the basic theory of quantum tunneling and Coulomb blockade in SETs. It then discusses modeling the SET using a master equation approach and simulating its DC characteristics such as current oscillations. Parameters like junction capacitance, gate capacitance, and temperature are varied to analyze their effect on SET characteristics.
- The document describes the design, modeling, and simulation of a fuzzy logic controlled static VAR compensator (SVC) for a transmission line.
- An SVC uses thyristor-controlled reactors and fixed capacitors to continuously regulate the voltage of a transmission line by absorbing or producing reactive power.
- A fuzzy logic controller is designed to control the firing angle of the thyristors to maintain a constant voltage at the receiving end of the transmission line for different load conditions. Simulations are carried out to demonstrate the effectiveness of the fuzzy controlled SVC.
Electrochemical methods are analytical techniques that use measurements of potential, charge, or current to determine an analyte's concentration or characterize its reactivity. They are divided into five major groups: potentiometry, voltammetry, coulometry, conductometry, and dielectrometry. Potentiometry measures the potential of a solution between two electrodes to relate it to an analyte's concentration. Voltammetry applies a constant or varying potential to measure the resulting current using a three-electrode system. Coulometry measures material deposited on an electrode during an electrochemical reaction using Faraday's laws. Conductometry measures the electrical conductivity of electrolyte solutions. Electrochemical techniques can be used to obtain thermodynamic data, study unstable
The study made in this paper concerns the use of the voltage-oriented control (VOC) of three-phase pulse width modulation (PWM) rectifier with constant switching frequency. This control method, called voltage-oriented controlwith space vector modulation (VOC-SVM). The proposed control scheme has been founded on the transformation between stationary (α-β) and and synchronously rotating (d-q) coordinate system, it is based on two cascaded control loops so that a fast inner loop controls the grid current and an external loop DC-link voltage, while the DC-bus voltage is maintained at the desired level and ansured the unity power factor operation. So, the stable state performance and robustness against the load’s disturbance of PWM rectifiers are boths improved. The proposed scheme has been implemented and simulated in MATLAB/Simulink environment. The control system of the VOC-SVM strategy has been built based on dSPACE system with DS1104 controller board. The results obtained show the validity of the model and its control method. Compared with the conventional SPWM method, the VOC-SVM ensures high performance and fast transient response.
This document describes using active disturbance rejection control (ADRC) for controlling a single-stage photovoltaic system connected to the electrical grid. It compares ADRC to the conventional perturb and observe (P&O) control method. ADRC combined with incremental conductance (ADRC-IC) is used for maximum power point tracking (MPPT) control. ADRC is also used to control the inverter to regulate the DC bus voltage and ensure unity power factor injection into the grid. The system aims to maximize power extraction from the PV array and regulate power injection into the grid with low harmonics.
A robust state of charge estimation for multiple models of lead acid battery ...journalBEEI
An accurate estimation technique of the state of charge (SOC) of batteries is an essential task of the battery management system. The adaptive Kalman filter (AEKF) has been used as an obsever to investigate the SOC estimation effectiveness. Therefore, The SOC is a reflexion of the chemistry of the cell which it is the key parameter for the battery management system. It is very complex to monitor the SOC and control the internal states of the cell. Three battery models are proposed and their state space models have been established, their parameters were identified by applying the least square method. However, the SOC estimation accuracy of the battery depends on the model and the efficiency of the algorithm. In this paper, AEKF technique is presented to estimate the SOC of Lead acid battery. The experimental data is used to identify the parameters of the three models and used to build different open circuit voltage–state of charge (OCV-SOC) functions relationship. The results shows that the SOC estimation based-model which has been built by hight order RC model can effectively limit the error, hence guaranty the accuracy and robustness.
Supercapacitors and Battery power management for Hybrid Vehicle Applications ...Pradeep Avanigadda
1. The document presents a study on using multi-boost and full-bridge converters for power management in hybrid electric vehicles combining supercapacitor and battery power sources.
2. Two converter topologies - multi-boost and multi-full bridge - are investigated for their suitability in distributing power from multiple supercapacitor modules to the vehicle's DC bus. Control strategies are developed for each topology.
3. Simulation and experimental results are presented for setups using 2 boost converters or 1 full-bridge converter, showing the converters can balance currents between supercapacitor modules and maintain the battery current level as required.
This document summarizes a measurement of the t-tbar production cross section using data from proton-proton collisions at 7 TeV collected by the CMS experiment at the LHC. The analysis selects events with one high-pT muon or electron, missing transverse energy, and hadronic jets, requiring at least one jet to be tagged as originating from a b quark. The measured cross section is 150 ± 9 (stat) ± 17 (syst) ± 6 (lumi) pb, consistent with higher-order QCD calculations. Combining with a previous CMS dilepton measurement gives 154 ± 17 (stat + syst) ± 6 (lumi) pb.
This paper was published by my former Supervisor and involves partly my calculations and the concepts used during my MSci Thesis at University College London.
This paper presents the three-phase CHB inverter fed induction motor suitable for renewable energy source applications. Normally, all present existing multilevel inverters produce multilevel output, but the number of components required is more, bulk in size, more in cost. Which are more burdens to small capacity renewable sources. These challenges are eliminated in CHB inverter. This CHB mainly consisting of one DC source, one capacitor and eight switches in each phase. To generate a five-level output in phase to ground voltage, it is required to maintain the capacitor voltage (V2) at fifty percent of the DC source voltage (V1). This capacitor voltage is regulated by a sensor less voltage regulating technique. The sensor less voltage regulation works without any sensor devices. We can implement this technique with very less cost compared to other techniques. The sensor less voltage regulation is realized by level-shifted sinusoidal pulse width modulation. The simulation results show a very good dynamic performance. Controller maintains the capacitor voltage at fifty percent of the source voltage irrespective of main source voltage changes and load changes. Inverter generates a five-level wave at the output from line to ground and seven-level wave from line to line with fewer Harmonic. It is implemented in matlab/simulink and showing good dynamic performance.
In this article, we have proposed a new control of a PV system connected to the grid. The goal is
to reduce current and voltage harmonicsfor increasing the quality of delivered energy. First, we have
modeled a PV panel. Then we have dimensioned the BOOST converter by finding L and C values. Next,
we have used Perturb and Observe (P&O) Maximum Power Point Control (MPPT) to improve energy
efficiency. Finally, We have developed a control of single-phase H-bridge inverter in order to eliminate the
3rd,5th,7th and 9th harmonics order, and added an LCLTo connect the PV inverter to the grid, an LCL
betweenthe inverter and the grid. Theperformance of the proposed system was tested by computing
spectrum and THD usingMatlab/Simulink software. The proposed architecture provides better Total
Harmonic Distortion (THD) which satisfy the EN50160 requirement the THD must be less than 4.66%. We
found that THD was decreased from 61.93% to 0.04%.
Certainly! The **basic principle of coulometry** involves passing a known electrical charge through a solution containing the analyte. Coulometry can be used to determine the amount of a substance in a solution, the purity of a compound, or the kinetics of an electrochemical reaction¹[3] ²[4]. It is a valuable technique in analytical electrochemistry for precision measurements of charge and is named after Charles-Augustin de Coulomb³[2]. One useful application of coulometry is determining the number of electrons involved in a redox reaction, which can be achieved through controlled-potential coulometric analysis using a known amount of a pure compound.
Auto tuning of frequency on wireless power transfer for an electric vehicleIJECEIAES
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2. Coulometry and Electro gravimetric Analysis
Electrogravimetry and coulometry are related methods in which
electrolysis is carried out for a sufficient length of time to ensure
complete oxidn or redn of the analyte to a product of known
composition.
In electrogravimetry, the goal is to determine the amount of analyte
present by converting it electolytically to a product that is weighed as
a deposit on one of the electrodes.
In coulometric procedures, we determine the amount of analyte by
measuring the quantity of electrical charge needed to completely
convert it to a product.
Electrogravimetry and coulometry are moderately sensitive and
among the most accurate and precise techniques available to the
chemist.
1/3/2020 2
3. Cont…
Electrogravimetry require no preliminary calibration against
chemical standards because the functional relationship b/n the quantity
measured and the analyte conc can be derived from theory and atomic
mass data.
When there is a net current in an electrochemical cell. The measured
potential across the 2 electrodes is no longer simply the d/ce b/n the 2
electrode potentials as calculated from the Nernst equation.
2 additional phenomena, IR drop & polarization must be considered
when current is present.
Because of these phenomena, potentials larger than the
thermodynamic potential are needed to operate an electrolytic cell.
When present in a galvanic cell, IR drop & polarization result in the
development of potentials smaller than predicted.
1/3/2020 3
4. Cont…
Coulometric methods of analysis are based on an
exhaustive electrolysis of the analyte.
By exhaustive we mean that the analyte is quantitatively
oxidized or reduced at the WE or reacts quantitatively with a
reagent generated at the WE.
There are 2 forms of coulometry: controlled-potential
coulometry, in which a constant potential is applied to the
electrochemical cell, and controlled-current coulometry, in
which a constant current is passed through the
electrochemical cell.
The total charge, Q, in coulombs, passed during electrolysis
is related to the absolute amount of analyte by Faraday’s law
Q = nFN ----------------------------8.1
1/3/2020 4
5. Cont…
Where n is the # of es transferred per mole of analyte, F is Faraday’s
constant (96487 C mol–1), and N is the moles of analyte.
A coulomb is also equivalent to an A.s; thus, for a constant current, i,
the charge is given as
Q = ite -----------------------------8.2
Where te is the electrolysis time.
If current varies with time, as it does in controlled potential
coulometry, then the total charge is given by
---------------8.3
In coulometry, current and time are measured, and equation 8.2 or
equation 8.3 is used to calculate Q.
Equation 8.1 is then used to determine the moles of analyte.
To obtain an accurate value for N, therefore, all the current must
result in the analyte’s oxidation or reduction.1/3/2020 5
6. Cont…
o In other words, coulometry requires 100% current efficiency (or an
accurately measured current efficiency established using a standard), a
factor that must be considered in designing a coulometric method of
analysis. 8.1. Controlled-Potential Coulometry
oThe easiest method for ensuring 100% current efficiency is to
maintain the WE at a constant potential that allows for the analyte’s
quantitative oxidn or redn, without simultaneously oxidizing or reducing
an interfering species.
o The current flowing through an electrochemical cell under a constant
potential is proportional to the analyte’s conc.
o As electrolysis progresses the analyte’s conc decreases as does the
current.
oThe resulting current vs time profile for controlled-potential
coulometry which also known as potentiostatic coulometry, shown in
Fig.8.1.1/3/2020 6
7. Cont…
o Integrating the area under the curve (equation 8.3), from t = 0 until t
= te, gives the total charge.
Fig.8.1.current-time curve for controlled potential coulometry.
1/3/2020 7
8. Selecting a Constant Potential
In controlled-potential coulometry, the potential is selected so that
the desired oxidn or redn rxn goes to completion without interference
from redox rxns involving other components of the sample matrix.
To see how an appropriate potential for the WE is selected, let’s
develop a constant-potential coulometric method for Cu2+ based on its
redn to Cu metal at a Pt cathode WE.
---------------- 8.4
•The potential needed for a quantitative redn of Cu2+ can be calculated
using the Nernst equation
-----------------8.5
1/3/2020 8
9. Minimizing Electrolysis Time
The current-time curve for controlled-potential coulometry in Fig.8.1
shows that the current decreases continuously throughout electrolysis.
An exhaustive electrolysis, therefore, may require a long time.
Since time is an important consideration in choosing and designing
analytical methods, the factors that determine the analysis time need to
be considered.
The change in current as a function of time in controlled-potential
coulometry is approximated by an exponential decay; thus, the current at
time t is i = i0e–kte----------------------8.6
Where i0 is the initial current and k is a constant that is directly
proportional to the area of the WE & the rate of stirring and inversely
proportional to the volume of the solution.
For an exhaustive electrolysis in which 99.99% of the analyte is
oxidized or reduced, the current at the end of the analysis, te, may be
approximated as i =(10–4)i0----------------------------------8.7
1/3/2020 9
10. Cont…
Substituting equation 8.7 into equation 8.6 and solving for te gives
the minimum time for an exhaustive electrolysis as
te= -k-1ln(10-4) = 9.21xk-1
From this equation increasing k leads to a shorter analysis time.
For this reason controlled-potential coulometry is carried out in
small-volume electrochemical cells, using electrodes with large
surface areas and with high stirring rates.
A quantitative electrolysis typically requires approximately 30–60
min, although shorter or longer times are possible.
1/3/2020 10
11. Instrumentation
The potential in controlled-potential coulometry is set using a 3-
electrode potentiostat.
Two types of WE are commonly used: a Pt electrode manufactured
from Pt-gauze & fashioned into a cylindrical tube & an Hg pool
electrode.
The large over potential for reducing H3O+ at mercury makes it the
electrode of choice for analytes requiring negative potentials.
For example, potentials more -ve than –1 V vs the SCE are feasible
at an Hg electrode but not at a Pt electrode, even in very acidic so/ns.
The ease, with which mercury is oxidized, however, prevents its use
at potentials that are +ve with respect to the SHE.
Platinum WEs are used when +ve potentials are required.
The auxiliary electrode, which is often a Pt wire, is separated by a
salt bridge from the solution containing the analyte.
1/3/2020
11
12. Cont…
This is necessary to prevent electrolysis products generated at the
auxiliary electrode from reacting with the analyte and interfering in
the analysis.
A saturated calomel or Ag/AgCl electrode serves as the RE.
The other essential feature of instrumentation for controlled-
potential coulometry is a means of determining the total charge
passed during electrolysis.
One method is to monitor the current as a function of time and
determine the area under the curve (see Fig.8.1).
Modern instruments, however, use electronic integration to monitor
charge as a function of time.
The total charge at the end of the electrolysis then can be read
directly from a digital readout or from a plot of charge versus time
(Fig.8.3).
1/3/2020 12
14. 8.2 Controlled-Current Coulometry
A second approach to coulometry is to use a constant current in
place of a constant potential (Fig.8.4).
Controlled-current coulometry also known as amperostatic
coulometry or coulometric titrimetry, has two advantages over
controlled-potential coulometry.
First, using a constant current makes for a more rapid analysis since
the current does not decrease over time.
Thus, a typical analysis time for controlled current coulometry is
less than 10 min, as opposed to approximately 30–60 min for
controlled-potential coulometry.
Second, with a constant current the total charge is simply the
product of current and time (equation 8.2).
A method for integrating the current–time curve, therefore, is not
necessary.
1/3/2020
14
15. Cont…
o Using a constant current does present two important experimental
problems that must be solved if accurate results are to be obtained.
o1st, as electrolysis occurs the analyte’s conc &, therefore, the current
due to its oxidation or reduction steadily decreases.
o To maintain a constant current the cell potential must change until
another oxidation or reduction rxn can occur at the WE.
o Unless the system is carefully designed, these secondary reactions
will produce a current efficiency of less than 100%.
o The second problem is the need for a method of determining when
the analyte has been exhaustively electrolyzed.
oIn controlled-potential coulometry this is signaled by a decrease in
the current to a constant background or residual current (see Fig.8.1).
oIn controlled-current coulometry, however, a constant current
continues to flow even when the analyte has been completely oxidized
or reduced.
1/3/2020 15
16. Cont…
A suitable means of determining the end-point of the rxn, te, is
needed.
Fig.8.4.current-time curve for controlled-current coulometry.
Maintaining Current Efficiency
To illustrate why changing the WE’s potential can lead to less than
100% current efficiency, let’s consider the coulometric analysis for
Fe2+ based on its oxidation to Fe3+ at a Pt WE in 1 M H2SO4.
Initially the potential of the WE remains nearly constant at a level
near the standard-state potential for the Fe3+/Fe2+ redox couple.
1/3/2020 16
17. Cont…
As the conc of Fe2+ decreases, however, the potential of the WE
shifts toward more +ve values until another oxidation rxn can provide
the necessary current.
Thus, in this case the potential eventually increases to a level at
which the oxidn of H2O occurs.
Since the current due to the oxidation of H3O+ does not contribute to
the oxidation of Fe2+, the current efficiency of the analysis is less than
100%.
To maintain a 100% current efficiency the products of any
competing oxidation rxns must react both rapidly and quantitatively
with the remaining Fe2+.
This may be accomplished, for example, by adding an excess of
Ce3+ to the analytical solution (Fig.8.5b).
When the potential of the WE shifts to a more +ve potential, the first
species to be oxidized is Ce3+.
1/3/2020 17
18. Cont…
The Ce4+ produced at the WE rapidly mixes with the so/n, where it
reacts with any available Fe2+.
---------------8.8
Combining these rxns gives the desired overall rxn of
In this manner, a current efficiency of 100% is maintained.
Furthermore, since the conc of Ce3+ remains at its initial level, the
potential of the WE remains constant as long as any Fe2+ is present.
This prevents other oxidation rxns, such as that for H2O, from
interfering with the analysis.
A species, such as Ce3+, which is used to maintain 100% current
efficiency, is called a mediator.
1/3/2020 18
19. Cont…
Instrumentation
Controlled-current coulometry normally is carried out using a
galvanostat and an electrochemical cell consisting of a WE and a
counter electrode.
The WE, which often is constructed from Pt, is also called the
generator electrode since it is where the mediator reacts to generate
the species reacting with the analyte.
The counter electrode is isolated from the analytical solution by a
salt bridge or porous frit to prevent its electrolysis products from
reacting with the analyte.
Alternatively, oxidizing or reducing the mediator can be carried out
externally, & the appropriate products flushed into the analytical so/n.
A so/n containing the mediator flows under the influence of gravity
into a small-volume electrochemical cell.
1/3/2020 19
20. Cont…
The products generated at the anode & cathode pass through separate
tubes, and the appropriate oxidizing or reducing reagent can be
selectively delivered to the analytical solution.
The other necessary instrumental component for controlled-current
coulometry is an accurate clock for measuring the electrolysis time, te,
and a switch for starting and stopping the electrolysis.
Analog clocks can read time to the nearest ±0.01 s, but the need to
frequently stop and start the electrolysis near the end point leads to a net
uncertainty of ±0.1 s.
Digital clocks provide a more accurate measurement of time, with
errors of ±1 ms being possible.
The switch must control the flow of current and the clock, so that an
accurate determination of the electrolysis time is possible
1/3/2020 20
21. Coulometric Titrations
Controlled-current coulometric methods commonly are called
coulometric titrations because of their similarity to conventional
titrations.
We already have noted, in discussing the controlled-current
coulometric determination of Fe2+, that the oxidation of Fe2+ by Ce4+ is
identical to the reaction used in a redox titration.
Combining equations 8.1 and 8.2 and solving for the moles of
analyte gives
------------------8.9
Compare this equation with the relationship b/n the moles of strong
acid, N, titrated with a strong base of known concentration.
N = (M base) (V base)
The titrant in a conventional titration is replaced in a coulometric
titration by a constant-current source whose current is analogous to the
titrant’s molarity.
1/3/2020 21
22. Cont…
oThe time needed for an exhaustive electrolysis takes the place of the
volume of titrant, and the switch for starting and stopping the
electrolysis serves the same function as a burette’s stopcock.
Quantitative Applications
o Coulometry may be used for the quantitative analysis of both
inorganic and organic compounds.
Controlled-Potential Coulometry
o The majority of controlled-potential coulometric analyses involve
the determination of inorganic cations and anions, including trace
metals and halides.
oThe ability to control selectivity by carefully selecting the WE’s
potential, makes controlled-potential coulometry particularly useful
for the analysis of alloys.
o For example, the composition of an alloy containing Ag, Bi, Cd, and
Sb can be determined by dissolving the sample and placing it in a
matrix of 0.2 M H2SO4. 1/3/2020
22
23. Cont…
A platinum WE is immersed in the solution and held at a constant
potential of +0.40 V versus the SCE.
At this potential Ag (I) deposits on the Pt electrode as Ag and the
other metal ions remain in solution.
When electrolysis is complete, the total charge is used to determine
the amount of silver in the alloy.
The potential of the Pt electrode is then shifted to –0.08 V vs the
SCE, depositing Bi on the WE.
When the coulometric analysis for bismuth is complete, antimony is
determined by shifting the WE’s potential to –0.33 V vs the SCE,
depositing Sb.
Finally, Cd is determined following its electrodeposition on the Pt
electrode at a potential of –0.80 V vs the SCE.
Another area where controlled-potential coulometry has found
application is in nuclear chemistry, in which elements such as
uranium and polonium can be determined at trace levels. 1/3/2020
23
24. Cont…
o For example, microgram quantities of uranium in a medium of
H2SO4 can be determined by reducing U (VI) to U (IV) at a Hg WE.
o Controlled-potential coulometry also can be applied to the
quantitative analysis of organic cpds, although the number of
applications is significantly less than that for inorganic analytes.
o One example is the six-electron reduction of a nitro group, –NO2, to
a primary amine, –NH2, at a mercury electrode.
Solutions of picric acid, for instance, can be analyzed by reducing to
triaminophenol.
o Another example is the successive reduction of trichloroacetate to
dichloroacetate, and of dichloroacetate to monochloroacetate
Cl3CCOO–(aq) + H3O+(aq) + 2e– ↔Cl2HCCOO–(aq) + Cl–(aq) +
H2O(l)
1/3/2020 24
25. Application Cont…
Cl2HCCOO–(aq) + H3O+(aq) + 2e– ↔ClH2CCOO–(aq) + Cl–(aq) +
H2O(l)
Mixtures of trichloroacetate and dichloroacetate are analyzed by
selecting an initial potential at which only the more easily reduced
trichloroacetate is reduced.
When its electrolysis is complete, the potential is switched to a more
negative potential at which dichloroacetate is reduced.
The total charge for the first electrolysis is used to determine the
amount of trichloroacetate, and the difference in total charge between
the first and second electrolyses gives the amount of dichloroacetate.
1/3/2020 25
26. Controlled-Current Coulometry
The use of a mediator makes controlled-current coulometry a more
versatile analytical method than controlled-potential coulometry.
For example, the direct oxidn or redn of a protein at the WE in
controlled-potential coulometry is difficult if the protein’s active
redox site lies deep within its structure.
The controlled-current coulometric analysis of the protein is made
possible, however, by coupling its oxidn or redn to a mediator that is
reduced or oxidized at the WE.
Controlled-current coulometric methods have been developed for
many of the same analytes that may be determined by conventional
redox titrimetry.1/3/2020 26
Application Cont…
27. Application Cont…
Coupling the mediator’s oxidn or redn to an acid–base,
precipitation, or complexation rxn involving the analyte allows for the
coulometric titration of analytes that are not easily oxidized or
reduced.
For example, when using H2O.
If the oxidn or redn of H2O is carried out externally using the
generator cell then H3O+ or OH– can be dispensed selectively into a
solution containing a basic or acidic analyte.
The resulting rxn is identical to that in an acid–base titration.
Coulometric acid–base titrations have been used for the analysis of
strong & weak acids and bases, in both aqueous & non-aqueous
matrices.
In comparison with conventional titrimetry, there are several
advantages to the coulometric titration.
1/3/2020 27
28. Cont…
One advantage is that the electrochemical generation of a “titrant”
that reacts immediately with the analyte allows the use of reagents
whose instability prevents their preparation & storage as a standard
so/n.
Thus, highly reactive reagents such as Ag2+ and Mn3+ can be used in
coulometric titrations.
Because it is relatively easy to measure small quantities of charge,
coulometric titrations can be used to determine small quantities of
analyte that cannot be measured accurately by a conventional
titration.
1/3/2020 28
29. Cont…
Example1. The purity of a sample of Na2S2O3 was determined by a
coulometric redox titration using I– as a mediator & I3
– as the “titrant.”
A sample weighing 0.1342 g is transferred to a 100-mL volumetric
flask & diluted to volume with distilled water. A 10.00-mL portion is
transferred to an electrochemical cell along with 25 mL of 1 M KI, 75
mL of a pH 7.0 phosphate buffer & several drops of a starch indicator
so/n. Electrolysis at a constant current of 36.45 mA required 221.8 s to
reach the starch indicator end point. Determine the purity of the
sample.
SOLUTION The coulometric titration of S2O3
2– with I3
– is Oxidizing
S2O3
2– to S4O6
2 –requires 1e per S2O3
2– (n = 1). Combining equations
8.1 & 8.2, and making an appropriate substitution for moles of
Na2S2O3 gives
1/3/2020 29
30. Cont…
represents the amount of Na2S2O3 in a 10.00-mL portion of a 100-mL
sample, thus 0.1325 g of Na2S2O3 is present in the original sample.
The purity of the sample, therefore, is
Note that the calculation is worked as if S2O3
2– is oxidized directly at
the WE instead of in so/n.
1/3/2020 30