# Introduction to Oxidation Reduction Potential Measurement

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Introduction to Oxidation Reduction Potential Measurement Dr. Axel W. Bier, Hach-Lange, Application Specialist Theory Oxidation Reduction Potential (ORP or Redox Potential) measures an aqueous system s capacity to either release or accept electrons from chemical reactions. When a system tends to accept electrons, it is an oxidizing system. When it tends to release electrons, it is a reducing system. A system s reduction potential may change upon introduction of a new species or when the concentration of an existing species changes. ORP values are used much like ph values to determine water quality. Just as ph values indicate a system s relative state for receiving or donating hydrogen ions, ORP values characterize a system s relative state for gaining or losing electrons. ORP values are affected by all oxidizing and reducing agents, not just acids and bases that influence ph measurement. From a water treatment perspective, ORP measurements are used often to control disinfection with chlorine or chlorine dioxide in cooling towers, swimming pools, potable water supplies, and other water analysis applications. For example, studies have shown that the life span of bacteria in water is strongly dependent on the ORP value. In wastewater, ORP measurement is used frequently to control treatment processes that employ biological treatment solutions for removing contaminants. Sensors ORP sensor operation works similarly to that of a standard ph sensor. A two-electrode system makes a potentiometric measurement. The ORP electrode serves as an electron donor or electron acceptor, depending upon the test solution. A reference electrode supplies a constant stable output for comparison. Electrical contact is made with the solution using a saturated potassium chloride (KCl) solution. The electrode behavior is defined by the Nernst equation: WHERE: E = measured potential (mv) between the platinum and the reference electrode E o = measured potential (mv) between the platinum and the reference electrode at a concentration of C ox = C red R = Universal gas constant (R = J mol -1 K -1 ) T = Temperature in K (Kelvin), where T (K) = t C and t is the temperature of the measured solution F = Faraday constant (96485 C mol -1 ) n = electrical charge of the ion C ox = oxidant concentration in moles/l C red = reductant concentration in moles/l. Platinum is normally used as the indicating sensor and the potential is measured against a reference electrode, usually Ag/AgCl. Other noble metals can also be used, such as gold or silver. Since the ORP potential is temperature dependent, temperature must also be recorded with every measurement in order to permit comparison of the two ORP values. Typically there is no automatic temperature compensation available in most commercial ORP meters. Continued on next page.

3 Table 1: mv Readings in ORP Standards Acceptance Criteria for Calibration For accurate sample measurements, check the ORP electrode performance against an ORP standard solution. The difference between the standard mv potential and the measured mv potential is called the offset. As long as the reference electrode is working properly, the ORP standard potential should be within ±10 mv for ORP probes in routine use, at a defined temperature. If desired, this offset may be subtracted from the sample mv readings. The Hach HQd Meter Series and IntelliCAL Probes automatically subtract this offset during sample measurement. With use over time, and depending on the type of sample, the platinum disk or ring may become coated with chemical and/or biological layers, which may cause a shift in potential (30-50 mv). Cleaning the probe periodically is therefore necessary. Electrode Cleaning If ORP measurements indicate a shift in potential over time, increased stabilization times or instable readings, electrode cleaning is recommended. Conduct cleaning with minimal sensor surface impact, starting with standard cleaning and if this does not help, aggressive cleaning (see instructions below). Be careful with your probe: Avoid aggressive and over frequent cleaning as it may be destructive and lead to ORP probe replacement. Standard Cleaning Procedures: A. Soak the probe for minutes in fresh tap water that contains a few drops of a commercial detergent such as dishwashing soap. Additionally, wipe the Pt surface with a cotton cloth, but take care not to damage any part of the probe. Afterwards, rinse with fresh tap water. B. Soak the probe for 15 minutes in 0.1 M hydrochloric acid (HCl). Following safety instructions, wipe the Pt surface with a cotton cloth or swab. Afterwards, rinse with fresh tap water. Aggressive Cleaning Procedures: C: Soak only the platinum element (not the reference junctions) for 1-2 hours in a 50:50 dilution of commercial chlorine bleach. NOTE: Make sure that the diaphragm (ceramic pin or open junction etc. ) is NOT in the chlorine bleach. Afterwards, rinse with fresh tap water and soak the probe for 1-2 hours in tap water to dilute the remaining bleach. It might be necessary to repeat the rinsing to remove all bleach from the probe; otherwise, the results of the calibration and sample measurement may be false due to the chlorine bleach. D: Polish the Pt surface with an abrasive paper of 600 grid or higher, or use an extra fine grinding paste and polish with a cotton cloth. Then soak the probe for 10 minutes in 1 M hydrochloric acid (HCl) and rinse thoroughly with fresh tap water. To achieve the best, most reproducible results, let the probe rest for several hours. After following the cleaning procedures described above (B,C,D), soak the ORP probe in the reference electrolyte solution overnight, then rinse with DI water and calibrate. The offset in an ORP standard should be a maximum of ± 20 mv. If the calibration is not satisfactory, or the offset is > 50 mv, replace the ORP probe.

4 Measurement in Various Applications Typically, probes should be calibrated to verify performance. An ORP standard should be used to determine the actual mv offset value for correction of measurement values. Take several readings in the same ORP standard to verify the final result. Calculate the offset with the following formula: E offset = E standard - E measured [mv] Add the mv offset to all sample results to adjust for the actual ORP probe performance. If necessary, also add the mv value for the reference system used to get the reference mv value for SHE (standard hydrogen electrode). E SHE = E offset + E reference + E measured [mv] Table 2: Ag/AgCl reference potentials vs. SHE NOTE: Unlike conductivity (a similar situation applies to ph), there is no automatic temperature compensation for ORP sample measurements. For ORP measurements, the temperature of the sample must always be recorded for further reference. Some samples may also require recording the actual ph value, because some Redox couples are ph dependent. Hach s HQd Meter Series allows calculation of the offset from an ORP standard measurement (ORP calibration) and stores the actual offset. This offset is then subtracted from each sample mv reading automatically. Drinking Water Drinking Water (DW) can be of very low ionic strength (e.g. 80 to 200 µs), causing problems with stabilization time and final readings. After ORP probe calibration, rinse the probe with some of the DW sample and transfer it into a new beaker filled with the DW sample. Wait at least 15 minutes for the first reading and then check every 5 minutes for stability. Depending on the temperature (lower values take longer), and on the conductivity (lower values take longer), it might take several hours to get a final reading. Most ph/orp meters offer a stability function with adjustable or pre-defined stability criteria. Refer to the IntelliCAL User Instructions for specific stability criteria information. Surface Water Typical surface water (SW) has a conductivity value exceeding 600 µs/cm, sometimes even in the ms/cm range. ORP measurement can be performed immediately following calibration. Because rivers, reservoirs and wells contain sufficient ORP active species, the measurement should be stable within 5 or 6 minutes. Rinse the probe after each measurement with tap water to remove any biological films from the Pt surface. This will help keep the Pt surface ready for measurement.

5 Wastewater The composition of Wastewater (WW) characteristically contains sufficient ionic strength, temperatures below 20 C, and a composition of chemical and biological contaminants. Depending on the location in the Wastewater Treatment Plant (WWTP) influent, aeration basin, nitrification/denitrification, effluent samples can show different ORP values. While the influent often comes with ORP readings around -200 mv, the WW stream changes the ORP to positive values of around +50 mv due to oxidation of the reducing species. ORP [ mv ] Process Development of methane Reduction of sulfate Reduction of iron Reduction of manganese Reduction of nitrate Table 3: Typical ORP values of WW in a WWTP ORP readings can be disturbed by air bubbles (aeration), floating particles, biological layers, etc. Therefore, it is essential for continuous ORP control to be based on measurement in the same location, at the same depth and under reproducible conditions. It may be faster to conduct a grab sample vs. waiting on a stable reading inside the basin or stream. After each WW measurement the probe needs to be cleaned first with DI water, then detergent solution, followed by a final rinse with DI water. Wipe the surface dry with a soft cloth and keep the probe in the recommended storage solution between measurements. This procedure will assure a long probe lifetime along with reproducible and accurate results. Standard Probe: For Laboratory Use Rugged Probe: For Field Use Call or visit: Lit. No J9 Printed in U.S.A. Hach Company, All rights reserved. Trademarks are the property of their respective owners.

### USEPA Direct Measurement Method 1, 2 Method µs/cm to ms/cm Conductivity Probe

Conductivity DOC316.53.01199 USEPA Direct Measurement Method 1, 2 Method 8160 0.01 µs/cm to 200.0 ms/cm Conductivity Probe Scope and application: For water and wastewater. 1 USEPA accepted for reporting

### Chapter 22: Introduction to Electroanalytical Chemistry

Chapter 22: Introduction to Electroanalytical Chemistry Two general categories: 1) Potentiometric Systems measure voltage (i.e., potential) of a galvanic cell (produces electricity spontaneously) 2) Voltammetric

### USEPA Electrode Method Method 8156

ph DOC316.53.01245 USEPA Electrode Method Method 8156 Scope and application: For drinking water 1, wastewater 2 and process water. 1 Based on Standard Method 4500-H+B, ASTM Method D1293-95 and USEPA Method

### ph Measurement and Control

ph Measurement and Control Tech Tip #14 1997 I. The Need for ph II. ph System Requirements III. ph Electrode Conditioning Procedures IV. How the electrode works V. Identifying the Electrode Components

### Direct ISE Method Method 8359 10 to 1000 mg/l Na + Sodium ISE

Sodium DOC316.53.01240 Direct ISE Method Method 8359 10 to 1000 mg/l Na + Sodium ISE Scope and application: For drinking water and process water. Test preparation Instrument-specific information This procedure

### Nitrogen, Ammonia. Known Addition ISE Method 1 Method 10002 Minimum of 0.8 mg/l NH 3 N. Ammonia ISE. Test preparation. Instrument-specific table

Nitrogen, Ammonia DOC316.53.01234 Known Addition ISE Method 1 Method 10002 Minimum of 0.8 mg/l NH 3 N Scope and application: For wastewater 2. Ammonia ISE 1 Adapted from the Standard Methods for the Examination

### ELECTROCHEMISTRY. Theory and Practice

ELECTROCHEMISTRY Theory and Practice Dr. Axel Bier Lab Product Application Manager - Electrochemistry For more information, please visit: www.hach.com/smartprobes P a g e 2 CONTENT INTRODUCTION 3 HOW TO

### Measurement by Ion Selective Electrodes

Measurement by Ion Selective Electrodes Adrian Vazquez May 8, 2012 Why Use Ion Selective Electrodes? Responsive over a wide concentration range Not affected by color or turbidity of sample Rugged and durable

### CARBON DIOXIDE. Instruction Manual HI Carbon Dioxide Ion Selective Electrode

HI 4105 CARBON DIOXIDE Instruction Manual HI 4105 Carbon Dioxide Ion Selective Electrode 1 HI 4105 Carbon Dioxide Electrode I. Introduction: The Hanna HI 4105 Carbon Dioxide gas sensing electrode is a

### Telephone: 760 930-6501 Fax: 760 930-0615 IQ Scientific Instruments, Inc. 2075-E Corte del Nogal Carlsbad, CA 92011

IQ Scientific Instruments, Inc. 2075-E Corte del Nogal Carlsbad, CA 92011 Telephone: 760 930-6501 Fax: 760 930-0615 www.phmeters.com Revision 4.5 2005 IQ Scientific Instruments, Inc. MODEL IQ140 ph Meter

### Figure 1. A voltaic cell Cu,Cu 2+ Ag +, Ag. gas is, by convention, assigned a reduction potential of 0.00 V.

Voltaic Cells Introduction In this lab you will first prepare a set of simple standard half-cells and then measure the voltage between the half-cells with a voltmeter. From this data you will be able to

### Direct Measurement Method Method 8157 0 to 20.0 mg/l (or 0 to 200% saturation) O 2 Clark-type Amperometric Sensor

Oxygen, Dissolved DOC316.53.01241 Direct Measurement Method Method 8157 0 to 20.0 mg/l (or 0 to 200% saturation) O 2 Clark-type Amperometric Sensor Scope and application: For water, wastewater and process

### Professional Plus. Calibration Tips

Professional Plus Calibration Tips Table of Contents Introduction...1 Calibration Worksheet...1 Temperature...3 Calibration Tips...3 Troubleshooting Tips...3 Conductivity...4 Calibration Tips...4 Troubleshooting

### 3.0 EXPERIMENT ON DETERMINATION OF CONDUCTIVITY

3.0 EXPERIMENT ON DETERMINATION OF CONDUCTIVITY Sl. No. Contents Preamble 3.1 Aim 3.2 Introduction 3.2.1 Environmental Significance 3.3 Principle 3.4 Materials Required 3.4.1 Apparatus Required 3.4.2 Chemicals

### HI 4101 AMMONIA. Instruction Manual HI Ammonia Ion Selective Electrode

HI 4101 AMMONIA Instruction Manual HI 4101 Ammonia Ion Selective Electrode 1 2 HI 4101 Ammonia Electrode I. Introduction: The Hanna HI 4101 Ammonia gas selective electrode is a combination electrode designed

### 430 ph Meter. Instruction Manual

40 ph Meter Instruction Manual This manual contains complete instructions for setting up and using the 40 ph meter. Applications information is also available. The information contained in this manual

### Model SOPs for EC measurement

Model SOPs for EC measurement Acid Deposition and Oxidant Research Center Electric Conductivity (1) Applicable samples (2) Principles and summary of the measurement method (3) References (4) Major instruments

### ph Measurements of Common Substances

Chem 100 Section Experiment 10 Name Partner s Name Introduction ph Measurements of Common Substances The concentration of an acid or base is frequently expressed as ph. Historically, ph stands for the

### No Brain Too Small. Credits: Four

No Brain Too Small Level 1 Science 2015 90944 Demonstrate understanding of aspects of acids and bases Credits: Four Achievement Achievement with Merit Achievement with Excellence Demonstrate understanding

### OPERATING INSTRUCTIONS

OPERATING INSTRUCTIONS Model IQ120 and IQ125 Professional ph Meter with Silicon Chip Sensor (IQ125 additional instructions printed in RED) IQ Scientific Instruments, Inc. 2075-E Corte del Nogal Carlsbad,

### ph Sensor Model 397 CAUTION SENSOR/PROCESS APPLICATION COMPATIBILITY WARNING ATEX DIRECTIVE Instruction Sheet PN 51A-397/rev.

Instruction Sheet PN 51A-397/rev.F January 2011 Model 397 ph Sensor For additional information, please visit our website at www.emersonprocess.com/raihome/liquid/. SPECIFICATIONS MODEL 397 PERFORMANCE

### Experiment 8 - Double Displacement Reactions

Experiment 8 - Double Displacement Reactions A double displacement reaction involves two ionic compounds that are dissolved in water. In a double displacement reaction, it appears as though the ions are

### Care, Maintenance, and Storage of YSI 6-Series Probes and Sondes

Tech Note Care, Maintenance, and Storage of YSI 6-Series Probes and Sondes Probe Care and Maintenance Periodic cleaning and membrane changes are required to keep your sensors operating properly. Follow

### The Cole-Parmer Chloride Ion Electrodes are used to quickly, simply, accurately, and economically measure chloride ions in aqueous solutions.

COLE-PARMER CHLORIDE ION ELECTRODES INSTRUCTION MANUAL GENERAL INSTRUCTIONS Introduction The Cole-Parmer Chloride Ion Electrodes are used to quickly, simply, accurately, and economically measure chloride

### COLE-PARMER LABORATORY CHLORIDE ION ELECTRODE INSTRUCTION MANUAL

COLE-PARMER LABORATORY CHLORIDE ION ELECTRODE INSTRUCTION MANUAL Cole-Parmer Instrument Company (800)323-4340 Fax:(847)247-2929 625 East Bunker Court, Vernon Hills, Illinois 60061 http://www.coleparmer.com

### New Chlorine Sensor Operates for Up to a Year Without Calibration or Maintenance

New Chlorine Sensor Operates for Up to a Year Without Calibration or Maintenance Most residual chlorine measurement systems require frequent calibration, maintenance and require constant flow, pressure

### Probably the greatest threat to softening resin is iron fouling. Cation resin will exchange ferrous iron Fe +2

Maintaining Ion Exchange Resin Based Systems by Michael C. Keller Sybron Chemicals Inc. Ion exchange resins use a process based upon ion selectivity. In this method, ions of greater preference will displace

### DETERMINATION OF EQUILIBRIUM CONSTANTS

DETERMINATION OF EQUILIBRIUM CONSTANTS USING GALVANIC CELLS PURPOSE The purpose of this experiment is to prepare several electrochemical cells and compare the relative voltages of the half-cells. This

### NCERT. To determine the concentration/molarity of KMnO 4

UNIT-6 TITRIMETRIC ANALYSIS (REDX REACTINS) THE oxidation and reduction reactions in aqueous solutions involve the transfer of electrons from one species to another. In the oxidation of a substance electron(s)

### Ch. 14: Potentiometry

Ch. 14: Potentiometry Outline: 14-1 Reference Electrodes 14-2 Indicator Electrodes 14-3 What is a Junction Potential? 14-4 How Ion-Selective Electrodes Work 14-5 ph Measurement with a Glass Electrode 14-6

### Measuring ph in Water or CaCl2 Using a ph Meter. Compiled by Darren Murray, June 30, 2011 TABLE OF CONTENTS OVERVIEW 3

Measuring ph in Water or CaCl2 Using a ph Meter Compiled by Darren Murray, June 30, 2011 TABLE OF CONTENTS OVERVIEW 3 PREPARING THE ph METER FOR USE (Calibration and Buffer Solutions) 4 When is Calibration

### AP FREE RESPONSE QUESTIONS ACIDS/BASES

AP FREE RESPONSE QUESTIONS ACIDS/BASES 199 D A chemical reaction occurs when 100. milliliters of 0.200molar HCl is added dropwise to 100. milliliters of 0.100molar Na 3 P0 solution. (a) Write the two net

### Determining Equivalent Weight by Copper Electrolysis

Purpose The purpose of this experiment is to determine the equivalent mass of copper based on change in the mass of a copper electrode and the volume of hydrogen gas generated during an electrolysis reaction.

### Welcome. Basics about ph-measurement. Dipl.-Ing. Manfred Schleicher

Welcome Basics about ph-measurement Dipl.-Ing. Manfred Schleicher This presentation helps for starting with ph-measurement Index Definition ph-value ph- electrode and temperature depency of ph measurement

### Lab 6 Two Weeks Characterization of Inorganic Compounds*

Lab 6 Two Weeks Characterization of Inorganic Compounds* *Taken from an Inorganic Lab course offered at Purdue University Chemical & Engineering News reported the levels of production for industrial chemicals

### Process Instrumentation

Table of Contents Page T1.2 Introduction T1.4 HI 504 T1.8 Panel Mounted Process Controllers T1.12 Wall Mounted Process Controllers T1.33 Dosing Pumps T1.50 Accessories for Dosing Pumps T1.58 Transmitters

### Table 212 Instrument-specific information. Instrument Sample cell Cell orientation. DR Fill line faces right

, Trak, 8317 DOC316.53.01054 Trak Fast Column Extraction Method Method 8317 5 to 150 µg/l Scope and Application: For drinking water Test preparation How to use instrument-specific information The Instrument-specific

### Chapter 16: Tests for ions and gases

The position of hydrogen in the reactivity series Hydrogen, although not a metal, is included in the reactivity series because it, like metals, can be displaced from aqueous solution, only this time the

### PT3 ULTRAPEN. myronl.com. ORP & Temperature Pen S ACCURATE S RELIABLE. S SIMPLE Professional Water Analysis. myronl.com/pt3.

ULTRAPEN PT3 ORP & Temperature Pen S ACCURATE S RELIABLE S SIMPLE Professional Water Analysis Accuracy of ±10 mv ORP Proprietary Sensor Design 99.9% Pure Platinum Electrode 3 Calibration Options with Automatic

### MODEL 370 ph/mv METER OPERATING MANUAL

MODEL 370 ph/mv METER OPERATING MANUAL 370 350/REV A/10-03 MODEL 370 ph/mv METER OPERATING INSTRUCTIONS CONTENTS Introduction 1 Specification 1 Installation 2 Displays 2-3 Controls 4 Operation 5 Calibration

### STOICHIOMETRY II UNIT

STOICHIOMETRY II UNIT Assignment #1 (Conversions with compounds) 1. Convert 1.806 x 10 23 molecules of Cl2 to moles. 2. Convert 1000 molecules of P4O10 to moles. 3. Convert 360 grams of NH3 (ammonia gas)

### Common Problems with Online Water Quality Analyzers. Greg Macy Director AquatiPro LLC

Common Problems with Online Water Quality Analyzers Greg Macy Director AquatiPro LLC Objectives Diagnosing Colorimetric Analyzers Identifying Common Problems with Sodium Analyzers Troubleshooting ph Analyzers

### Sartorius Basic ph Meter PB-20

98648-009-18 Sartorius Basic ph Meter PB-20 Operation Manual Contents Page General View 4 Warning and Safety Information 5 Basic ph Meter Quick Reference 6 Installing and Maintaining Electrodes 8 Standardizing

### Disinfection Sensor Technical Notes

Disinfection Sensor Technical Notes Measuring Principles Our disinfection sensors utilize one of two measuring principles. Two Electrode System DC Voltage is applied between reference/counter electrode

### Determining Equivalent Weight by Copper Electrolysis

Purpose To determine the equivalent mass of copper based on change in the mass of a copper electrode and the volume of hydrogen gas generated during an electrolysis experiment. The volume of hydrogen gas

### The Control of ph and Oxidation Reduction Potential (ORP) in Cooling Tower Applications By Charles T. Johnson, Walchem Corporation

The Control of ph and Oxidation Reduction Potential (ORP) in Cooling Tower Applications By Charles T. Johnson, Walchem Corporation Introduction The importance of keeping cooling tower water in proper chemical

### Milwaukee USER MANUAL

Milwaukee USER MANUAL PORTABLE DISSOLVED OXYGEN METER MODEL: MW600 Smart DO Meter PROBE PREPARATION: The meter is supplied with a 9V battery. Slide off the battery compartment cover on the back of the

### This value, called the ionic product of water, Kw, is related to the equilibrium constant of water

HYDROGEN ION CONCENTRATION - ph VALUES AND BUFFER SOLUTIONS 1. INTRODUCTION Water has a small but definite tendency to ionise. H 2 0 H + + OH - If there is nothing but water (pure water) then the concentration

### WATER CHEMISTRY AND POOL WATER BALANCE

C R6 H A PT E WATER CHEMISTRY AND POOL WATER BALANCE LEARNING OBJECTIVES After completely studying this chapter, you should be able to: Understand and list the parameters upon which water balance is based.

### Experiment 9 - Double Displacement Reactions

Experiment 9 - Double Displacement Reactions A double displacement reaction involves two ionic compounds that are dissolved in water. In a double displacement reaction, it appears as though the ions are

### Experiment 16-Acids, Bases and ph

Definitions acid-an ionic compound that releases or reacts with water to form hydrogen ion (H + ) in aqueous solution. They taste sour and turn litmus red. Acids react with certain metals such as zinc,

### STANDARD OPERATING PROCEDURES

PAGE: 1 of 6 CONTENTS 1.0 SCOPE AND APPLICATION 2.0 METHOD SUMMARY 3.0 SAMPLE PRESERVATION, CONTAINERS, HANDLING AND STORAGE 4.0 INTERFERENCES AND POTENTIAL PROBLEMS 5.0 EQUIPMENT/APPARATUS 6.0 REAGENTS

### CYCLE CHEMISTRY ph MEASUREMENT

CYCLE CHEMISTRY ph MEASUREMENT David M. Gray and Edward P. Santini Thornton Associates, Waltham MA Electric Utility Chemistry Workshop Champaign, Illinois May 12-14, 1998 Sponsored by University of Illinois

### Chapter 13: Electrochemistry. Electrochemistry. The study of the interchange of chemical and electrical energy.

Chapter 13: Electrochemistry Redox Reactions Galvanic Cells Cell Potentials Cell Potentials and Equilbrium Batteries Electrolysis Electrolysis and Stoichiometry Corrosion Prevention Electrochemistry The

### Introductory Chemistry

Introductory Chemistry Lab 9: Acids and Bases Objectives Understand the properties and reactions of acids and bases Relate these properties to common household products Introduction Have you ever had

### Importance of ph. ph plays an important role in everyday life. Water Treatment. many treatment processes are ph dependent

ph Adjustment Importance of ph ph plays an important role in everyday life blood in our bodies growing vegetables plating chrome on car bumpers Water Treatment many treatment processes are ph dependent

### PART 1 - INTRODUCTION...

Table of Contents PART 1 - INTRODUCTION... 3 1.1 General... 3 1.2 Sensor Features... 3 1.3 Sensor Specifications (CDE-45P)... 4 Figure 1-1 CDE-45P Sensor Dimensions (standard, convertible style)... 4 PART

### environmental engineering master degree Department of Hydraulic, Geotechnical & Environmental Engineering ABSTRACT

U N I V E R S I T Y O F N A P L E S " F E D E R I C O I I " environmental engineering master degree Department of Hydraulic, Geotechnical & Environmental Engineering ABSTRACT Localization of Corrosion

### Electrochemistry: Voltaic Cells

Electrochemistry: Voltaic Cells Computer 20 In electrochemistry, a voltaic cell is a specially prepared system in which an oxidation-reduction reaction occurs spontaneously. This spontaneous reaction produces

### 440 ph Meter. Instruction Manual

440 ph Meter Instruction Manual This manual contains complete instructions for setting up and using the 440 ph meter. Applications information is also available. The information contained in this manual

### Chlorides in Water. Based on the standard ISO 9297:2000 DOC Introduction

Chlorides in Water DOC316.52.93091 Based on the standard ISO 9297:2000 1. Introduction As tap water, surface water or mineral water contain chloride ions at low concentration levels, chloride determination

### Definition of ph ph is defined as the negative logarithm

Common Acids 1M HCl: 0.0 ph Sulfuric Acid: 0.3 ph Lemon Juice: 2.0 ph Vinegar: 3.0 ph Wine: 3.5 ph Beer: 4.5 ph Milk: 6.0 ph Common Bases Egg Whites: 7.5 ph Seawater: 8.0 ph Sodium Bicarbonate: 8.4 ph

### QUESTION (2012:3) (a) (i) Complete the table below showing the conjugate acids and bases. CO 3 H 2 O OH HCN CN -

QUESTION (2012:3) (i) Complete the table below showing the conjugate acids and bases. Conjugate acid Conjugate base - HCO 3 2 CO 3 H 2 O OH HCN CN - (ii) HPO 4 2 (aq) Write equations for the reactions

### Techneau, 08.October Redesigned monitoring station based on UV/Vis spectrometry

Techneau, 08.October 2007 Redesigned monitoring station based on UV/Vis spectrometry Techneau, 08.October 2007 Redesigned monitoring station based on UV/Vis spectrometry 2006 TECHNEAU TECHNEAU is an Integrated

### 12.1 How do sub-atomic particles help us to understand the structure of substances?

12.1 How do sub-atomic particles help us to understand the structure of substances? Simple particle theory is developed in this unit to include atomic structure and bonding. The arrangement of electrons

### Denver Instrument Company. BASIC ph Meter. Operation Manual 300408.1 Rev. G

Denver Instrument Company BASIC Meter Operation Manual 300408.1 Rev. G BASIC Meter Quick Reference 1. Connect power cable to meter power jack and to AC power source. 2. Connect a glass electrode to the

### Turn in your graphs and pages 9-12 ONLY

CHEM 152 WINTER 2010 POTENTIOMETRIC TITRATIONS Fill-in, Prelab attached (p 12) Name Turn in your graphs and pages 9-12 ONLY LEARNING OBJECTIVES: After completing this experiment, you should feel comfortable:

### Synthesis of a Coordination Compound Containing Iron and Analysis of this Compound Using Redox Methods Prelab

Synthesis of a Coordination Compound Containing Iron and Analysis of this Compound Using Redox Methods Prelab Name Total /10 NOTE: AT THIS POINT YOU WILL ANSWER ALL PRELAB QUESTIONS IN YOUR CARBON COPY

### 13.0 EXPERIMENT ON DETERMINATION OF BIOCHEMICAL OXYGEN DEMAND

13.0 EXPERIMENT ON DETERMINATION OF BIOCHEMICAL OXYGEN DEMAND Sl. No. Contents Preamble 13.1 Aim 13.2 Introduction 13.2.1 Environmental Significance 13.3 Principle 13.4 Materials Required 13.4.1 Apparatus

### white paper reviews why the chlor-alkali process is so damaging to ph electrodes and discusses a sensor design that has

INGOLD White Paper Leading Process Analytics No More Tears Elevated temperatures, presence of chlorine and high salt concentration throughout the chlor-alkali process make stable and reliable ph measurement

### Milwaukee USER MANUAL. Milwaukee. Smart DO Meter PORTABLE DISSOLVED OXYGEN METER MODEL: SM600. Authorized Dealer: ISMIL600 11/01

Milwaukee Milwaukee USER MANUAL PORTABLE DISSOLVED OXYGEN METER MODEL: SM600 Smart DO Meter Authorized Dealer: ISMIL600 11/01 PROBE PREPARATION: The meter is supplied with a 9V battery. Slide off the battery

### Lab 10: RedOx Reactions

Lab 10: RedOx Reactions Laboratory Goals In this laboratory, you will: develop a basic understanding of what electrochemical cells are develop familiarity with a few different examples of redox reactions

### Ion Selective Electrodes

Ion Selective Electrodes OAKTON has a large selection of Ion Selective Electrodes () to suit a wide variety of applications. Each electrode has a typical response time of 20 to 30 seconds but will vary

### ACID-BASE TITRATIONS: DETERMINATION OF CARBONATE BY TITRATION WITH HYDROCHLORIC ACID BACKGROUND

#3. Acid - Base Titrations 27 EXPERIMENT 3. ACID-BASE TITRATIONS: DETERMINATION OF CARBONATE BY TITRATION WITH HYDROCHLORIC ACID BACKGROUND Carbonate Equilibria In this experiment a solution of hydrochloric

### Carbonate to Halide Conversion

Conversion Objective The theoretical yield of the reaction product and the ratio of products to reactants will be predicted using the Law of Conservation of Matter and the Law of Definite Composition.

### Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1. A chemical equation. (C-4.4)

Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1 1. 2. 3. 4. 5. 6. Question What is a symbolic representation of a chemical reaction? What 3 things (values) is a mole of a chemical

### Lab #13: Qualitative Analysis of Cations and Anions

Lab #13: Qualitative Analysis of Cations and Anions Objectives: 1. To understand the rationale and the procedure behind the separation for various cations and anions. 2. To perform qualitative analysis

### 1. Cyclic Voltammetry At Solid Electrodes

Experiments in Analytical Electrochemistry 1. Cyclic Voltammetry At Solid Electrodes PURPOSE: To learn the basics of cyclic voltammetry with a well-behaved echem system BACKGROUND: Cyclic voltammetry (CV)

### 21 st Century Chemistry Structured Question in Topic 1 Planet Earth Unit 1-4

21 st Century Chemistry Structured Question in Topic 1 Planet Earth Unit 1-4 1. Air consists of oxygen and other substances. (a) Is oxygen an element or a compound? Explain briefly. It is an element. [1]

### 6. A Six-Bottle Study of Ionic Compounds

6. A Six-Bottle Study of Ionic Compounds What you will accomplish in this experiment In last week s experiment, you observed a chemical change: a chemical reaction that resulted in a change in the composition,

### CONDUCTIVITY SENSOR. Description D0382. Figure 1. The Conductivity Sensor

CONDUCTIVITY SENSOR Description D0382 Figure 1. The Conductivity Sensor Short Description The Conductivity Sensor can be used to measure either solution conductivity or total ion concentration of aqueous

### Total Acid Number (TAN) (ASTM D664)

Total Acid Number (TAN) (ASTM D664) DOC316.52.93095 Potentiometric titration Application: Petrochemical oils 1. Introduction This working procedure deals with the titration of Total Acid Number (TAN) in

### LABORATORY TESTING GRAB SAMPLES COMPOSITE SAMPLES GENERAL LABORATORY SAFETY

LABORATORY TESTING Sampling and laboratory analysis of source water and finished water are part of every water treatment plant operator's daily routine. Sampling and testing are necessary to gather data

### GA/7 Potentiometric Titration

Rev. 7/99 7-1 INTRODUCTION GA/7 Potentiometric Titration The potentiometric titration is a useful means of characterizing an acid. The ph of a solution is measured as a function of the amount of titrant

### Molarity of Ions in Solution

APPENDIX A Molarity of Ions in Solution ften it is necessary to calculate not only the concentration (in molarity) of a compound in aqueous solution but also the concentration of each ion in aqueous solution.

### Electrochemistry: Voltaic Cells. Evaluation copy. Figure 1

Electrochemistry: Voltaic Cells Computer 20 In electrochemistry, a voltaic cell is a specially prepared system in which an oxidation-reduction reaction occurs spontaneously. This spontaneous reaction produces

### Oxidation of Isoborneol to Camphor

Oxidation of Isoborneol to Camphor Organic Redox A simple way to think about organic redox is that it is really an increase in the electronegativity or electropositivity of carbon due to functional group

### IONIC REACTIONS in AQUEOUS SOLUTIONS: NET IONIC EQUATIONS AB + CD AD + CB

35 IONIC REACTIONS in AQUEOUS SOLUTIONS: NET IONIC EQUATIONS Double replacements are among the most common of the simple chemical reactions. Consider the hypothetical reaction: AB + CD AD + CB where AB

### ANALYSIS OF SODA ASH

Chemistry Experiment 213 ANALYSIS OF SODA ASH The objectives of this experiment are to: LEARNING OBJECTIVES - understand the titration curve for a diprotic base. - use the titration curve to calculate

### ANALYSIS of DRAIN CLEANERS WITH a ph METER

ANALYSIS of DRAIN CLEANERS WITH a ph METER LAB PH 3 From Juniata College SIM INTRODUCTION Most common household cleaners contain acids or bases. Acidic cleaners, such as toilet bowl cleaners, often contain

### 4.9 Oxidation-Reduction Reactions

4.9 Oxidation-Reduction Reactions We have seen that many important substances are ionic. Sodium chloride, can be formed by the reaction of elemental sodium and chlorine: 2Na(s) Cl 2 (g) 2NaCl(s) This process

### Titration Principles

Titration Principles General Principles Volumetric analysis refers to a collection of methods in which the volume of a solution of accurately known concentration, the standard solution, required to react

### General Chemistry I (FC, 09-10) Lab #3: The Empirical Formula of a Compound. Introduction

General Chemistry I (FC, 09-10) Introduction A look at the mass relationships in chemistry reveals little order or sense. The ratio of the masses of the elements in a compound, while constant, does not

### Laboratory & Field Water Analysis Essentials

Laboratory & Field Water Analysis Essentials FEATURED INSIDE! HQd Benchtop Meters Page 7 5 New ISE IntelliCAL Probes Pages 11-12 sension + Meters & Probes Pages 14-21 2100Q Portable Turbidimeter Page 49

### 3 Solutions of Acids and Bases

CHAPTER 3 3 Solutions of Acids and Bases SECTION Chemical Compounds BEFORE YOU READ After you read this section, you should be able to answer these questions: What are strong and weak acids? What are strong

### Q1. The chart shows the processes involved in the manufacture of nitric acid from ammonia.

Chemistry C2 Foundation and Higher Questions Q1. The chart shows the processes involved in the manufacture of nitric acid from ammonia. (a) Complete the word equation for the reaction that takes place

### Cadmium Reduction Method Method 8039 0.3 to 30.0 mg/l NO 3 N (HR) Powder Pillows or AccuVac Ampuls

Nitrate DOC316.53.01066 Cadmium Reduction Method Method 8039 0.3 to 30.0 mg/l NO 3 N (HR) Powder Pillows or AccuVac Ampuls Scope and application: For water, wastewater and seawater. Test preparation Instrument-specific

### Electrochemistry. Standard ph Electrodes. Speciality ph & ORP Electrodes. electrodes

Standard ph Electrodes All are supplied with 1 m of cable and BNC plug (+ 2 banana plugs built-in ATC) SP10B, SP10T SP10B: ph SP10T: ph + ATC (Pt) SP20B, SP20T SP20B: ph SP20T: ph + ATC (Pt) Speciality