OXIDATION-REDUCTION TITRATIONS-Permanganometry

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "OXIDATION-REDUCTION TITRATIONS-Permanganometry"

Transcription

1 Experiment No. Date OXIDATION-REDUCTION TITRATIONS-Permanganometry INTRODUCTION Potassium permanganate, KMnO 4, is probably the most widely used of all volumetric oxidizing agents. It is a powerful oxidant and readily available at modest cost. The intense color of the permanganate ion, MnO 4-, is sufficient to detect the end point in most titrations. Depending upon reaction conditions permanganate ion is reduced to manganese in the +, 3+, 4+ or 6+ state. In solutions that are 0.1 M or greater in mineral acid the common reduction product is manganese (II) ion MnO H + + 5e - Mn + + 4H O E 0 = 1.51 V This is the most widely used of the permanganate reactions. In solutions that are weakly acidic (above ph 4) neutral, or weakly alkaline manganese dioxide is the most common reduction product MnO H + + 3e - MnO (s) + H O E 0 = 1.70 V Titration in which manganese dioxide is the product suffer from the disadvantage that the slightly soluble brown oxide obscures the end point; time must be allowed for the solid to settle before an excess of the permanganate can be detected. Some important volumetric analyses based on permanganate involve reduction to manganese ion according to the half reaction given below; MnO e - MnO 4 - E 0 = 0.56 V This stoichiometry tends to predominate in solutions that are greater than 1 M in sodium hydroxide. Alkaline oxidations with permanganate have proved to be most useful in the determination of organic compounds.

2 REAGENTS AND APPARATUS FeSO 4.7H O, Ca(NO 3).4H O, H O for unknowns Potassium permanganate, KMnO 4: 1.0 L of 0.00 M (for 4 students) Sodium oxalate, Na C O 4 (primary standard in desiccator) Ammonium oxalate, (NH 4) C O 4.H O (solid in the balance room) Methyl orange (in droppers) Stannous chloride, SnCl (already prepared) Mercury (II) Chloride, HgCl (already prepared) Preventive solution (or Zimmermann-Reinhart reagent) (already prepared) Sulfuric acid, H SO 4, 500 ml of 0.75 M (for students) Hydrochloric acid, HCl, 5 ml of 6.0 M (for each student) Ammonia, NH 3, 5 ml of 6.0 M (for each student) Sulfuric acid, H SO 4, 50 ml of 3.0 M (for students) 0.1 M AgNO 3 (in droppers) Blue band filter paper ( for each student) Glass wool buret Watch glass 50 ml conical flasks x ( for each student) 100 ml graduated cylinder PROCEDURE A) Preparation and Standardization of KMnO 4 Solution 1) Prepare 1.0 L of 0.00 M KMnO 4 in distilled water for 4 students. Pour into a 1.0 L beaker. ) Keep the solution at a gentle boil for about 1 hour. Distilled water may contain organic matter which will reduce MnO 4 - ion. The solution is heated in order to hasten the oxidation of this material and coagulate the colloidal precipitate of MnO which forms as a reduction product: MnO - 4 reducing agent MnO oxidation product (in neutral solution) 3) Cover and let stand overnight. 4) Remove MnO by filtration using glass wool. Particles of MnO should be removed since these particles catalyze further decomposition of the solution. Filter paper can not be used for filtering because permanganate ion reacts with it to form additional manganese dioxide. 5) Store the solution in a clean, glass-stoppered amber bottle and keep in the dark when not in use.

3 B) Standardization of Permanganate Solution with Sodium Oxalate 1) Weigh 0. to 0.3 g (0.1 mg) dry primary standard Na C O 4 into 50 ml Erlenmeyer flasks. ) Dissolve the sodium oxalate in 75.0 ml of 0.75 M H SO 4. 3) Heat the solution to 80 to 90 C and titrate with KMnO 4, do not boil the solution. End point is permanent pink color (~30 s). The net reaction in the titration can be written as follows: - MnO 4 5CO4 16H Mn 10CO 8HO Promptly wash any KMnO 4 that spatters on the walls of the beaker into the bulk of the liquid with a stream of water. Finely divided MnO will form along with Mn + if the KMnO 4 is added too rapidly and will cause the solution to acquire a faint brown discoloration. Precipitate formation is not a serious problem as long as sufficient oxalate remain to reduce the MnO to Mn + ; the titration is simply discontinued until the brown color disappears. The solution must be free of MnO at the end point. 4) Repeat the titration with one additional sample. 5) Determine a blank by titrating an equal volume of 0.75 M H SO 4. Correct the titration data for the blank. 6) Your partners will do the standardization experiment twice. Record the results of all titrations (totally 8 titrations) and calculate the molarity of the KMnO 4 solution for eigth replicates and at the end calculate the average of molarity of KMnO 4 solution. C) Determination of Iron 1) Take your unknown sample into a 50 ml Erlenmeyer flask and place it in a steam bath and evaporate to a volume of about 10 ml. The solution will probably show the yellow color of ferric ion at this stage. Estimate the volume comparison with 10 ml of water in a similar beaker. Reduction of stannous chloride must be carried out in a relatively concentrated solution in order the point at which reaction is complete can be determined by the change in color. ) Treat each unknown solution individually. 3) While still hot, add SnCl solution a drop at a time until color changes to light green. The first drop added may be sufficient to reduce all Fe 3+ present. The reaction is given below: Fe 3 Sn Fe Sn 4 4) Add two drops of SnCl solution in excess after the color change is observed. 5) Cool the solution to room temperature and pour in rapidly 0.0 ml mercuric chloride, HgCl solution.

4 The excess reducing agent is eliminated by addition HgCl. The slightly soluble mercury (I) chloride (Hg Cl ) does not reduce permanganate, nor does the excess mercury (II) chloride (HgCl ) reoxidize iron (II). Sn HgCl Hg Cl (s) 4 Sn Cl If the reagent is not added all at once, there may be a local excess of stannous ion which will cause the reduction of HgCl to Hg rather than Hg Cl mercurous chloride. Elemental Hg(l) reacts with permanganate and causes the results of the analysis to be high. 4 Sn HgCl Hg(l) Sn Cl The precipitate should be small in amount and of a pure white color. A grayish precipitate indicates reduction to mercury. This reacts slowly with permanganate and will not give true titration values. If no precipitate appears, it means that not enough stannous chloride has been added. If a small white precipitate is not obtained, the sample is spoiled and should be discarded. 6) Allow to stand minutes and then add 100 ml distilled water. 7) Add 0.0 ml preventive solution and titrate immediately with permanganate. The net reaction in the titration can be written as follow: 5Fe MnO 8H 5Fe 3 Mn 4H O 4 The reaction of iron(ii) with permanganate is smooth and rapid. The presence of iron (II) in the reaction mixture, however, induces the oxidation of chloride ion by permanganate, a reaction that does not ordinarily proceed rapidly enough to cause serious error. High results are obtained if this parasitic reaction is not controlled. Its effects can be eliminated through removal of the hydrochloric acid by evaporation with sulfuric acid or by the addition of Zimmermann-Reinhart reagent, which contains manganese (II) in a fairly concentrated mixture of sulfuric and phosphoric acid. The oxidation of chloride ion during a titration is believed to involve a direct reaction between this species and the manganese(ii) ions that form as an intermediate in the reduction of permanganate ion by iron (II). The presence of manganese(ii) in the Zimmermann-Reinhart reagent is belived to inhibit the formation of chlorine by decreasing the potential of the manganese(iii)/manganese(ii) couple. Phosphate ion is believed to exert a similar effect by forming stable manganese(iii) complexes. Moreover, phosphate ions react with iron(iii) to form nearly colorless complexes so that the yellow color of the iron(ii)/chloro complexes doe not interfere with the end point. 8) Determine a blank by adding two drops of stannous chloride to 100 ml of distilled water in a 50 ml Erlenmeyer flask; then proceed with addition of 0.0 ml of mercuric chloride, 0.0 ml of preventive solution and 100 ml of distilled water just in the titration of a sample. Note the volume of permanganate needed to give the same color as the end point reached in the titrations. 9) Subtract the blank from the total volume used to obtain the net volume for each portion of unknown sample.

5 10) Report the result as mg iron. D) Determination of Hydrogen Peroxide 1) Take your unknown sample into a 50 ml Erlenmeyer flask and add 100 ml distilled water. ) Treat each unknown solution individually. 3) Add 7.0 ml of 3.0 M H SO 4. 4) Titrate with standard KMnO 4 solution. End point is the first pink color that persists for minutes. 5) Report the result as mg H O. The net reaction in the titration is 5H O MnO Mn 4 6H 5O 8H O E) Determination of Calcium 1) Take your unknown sample into a 50 ml Erlenmeyer flask and add 100 ml distilled water ) Treat each unknown solution individually. 3) Add 10.0 ml of 6.0 M HCl. 4) Heat to 60 C to 80 C and then add 3.0 g of (NH 4) C O 4.H O. 5) Add 3 drops of methyl orange indicator, then introduce 6.0 M NH 3 dropwise from pipette until the color changes from red to yellow. 6) Allow the solution to stand half an hour. 7) Filter the solution through a blue band filter paper. 8) Wash the beaker and precipitate with 10 to 0 ml portions of distilled water until the washings show a faint cloudiness when tested with an acidified AgNO 3 solution. After enough washings almost all Cl - ions can be removed. 9) Place the filter in which the precipitate was formed in a 50 ml Erlenmeyer flask. Add 50.0 ml of distilled water and 50.0 ml of 3.0 M H SO 4. CaC O (s) 4 H Ca H C O 4 10) Heat to 80 to 90 C to dissolve the precipitate. Titrate with standardized KMnO 4 solution with filter paper. The temperature of the solution should not be allowed to drop below 60 C. Take as an end point the first pink color that persists for 15 to 0 sec. The net reaction in the titration is given below: 5H C O MnO 6H ) Report the result as mg Ca. Mn 10CO 8H O

6 PRE-LAB STUDIES Read pages from the textbook (9 th Ed) 1) Why KMnO 4 is preferred as an oxidizing agent in redox titrations? ) What is the aim of heating KMnO 4 during its preparation step? Explain and write the related reaction equations. 3) What is the importance of filtering KMnO 4 solution and why do we use glass-wool instead of filter-paper? 4) Explain the importance of heating the solution to 80 to 90 C in the standardization of KMnO 4. 5) Why should the medium be acidic in KMnO 4 standardization? 6) What is the aim of adding SnCl in Fe determination? Write the related reaction equations. 7) What are the function(s) of preventive solution? Explain. 8) Why an indirect method is applied for Ca + determination? POST-LAB STUDIES 1) Why do we perform the titrations slowly? ) During standardization of KMnO 4 if you observe a brown precipitate, what does this indicate? Do you continue the titration in this situation or stop and repeat it? 3) Why do we perform blank analysis in KMnO 4 standardization? 4) Why do we add HgCl and why do we add it quickly? Write the related reaction equations. 5) If you add HgCl slowly what will you observe and how does this affect your result? 6) Why should the ph of the medium be about 4 in Ca + determination? How do we adjust this ph? 7) Why do we use NH 3 but not NaOH for ph adjustment in Ca + determination?

7 Name surname: Section: Date: REPORT SHEET FOR PERMANGANOMETRY B. Standardization of Permanganate Solution with Sodium Oxalate Replicates 1 Group Members: Name, Surname Mass of Na C O 4, g Blank corrected volume of KMnO 4, ml Concentration of KMnO 4, M Concentration of KMnO 4, M (X s) C. Determination of Iron Replicates Blank corrected volume of KMnO 4, ml Mass of iron, mg Mean mass, mg (X s) True mass of iron, mg % Relative Error 1 The following information (true values) will be sent to your address: Concentration of iron in the unknown solution= Volume of iron unknown, ml= TA`s Name and Signature:

8 D. Determination of Hydrogen Peroxide Replicates Volume of KMnO 4, ml Mass of H O, mg Mean mass, mg (X s) True mass of H O, mg % Relative Error 1 The following information (true values) will be sent to your address: Concentration of H O in the unknown solution= Volume of H O unknown, ml= E. Determination of Calcium Replicates 1 Volume of KMnO 4, ml Mass of calcium, mg Mean mass, mg (X s) True mass of Ca, mg % Relative Error The following information (true values) will be sent to your address: Concentration of calcium in the unknown solution= Volume of calcium unknown, ml= TA`s Name and Signature:

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 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

More information

Experiment 8: Synthesis and Analysis of an Inorganic Compound CH3500: Inorganic Chemistry, Plymouth State University

Experiment 8: Synthesis and Analysis of an Inorganic Compound CH3500: Inorganic Chemistry, Plymouth State University Experiment 8: Synthesis and Analysis of an Inorganic Compound CH3500: Inorganic Chemistry, Plymouth State University Adapted from Johnson, R.C. "Convenient procedure for the preparation of potassium trioxalatoferrate(iii),"

More information

Coordination Compounds. Introduction - Part I

Coordination Compounds. Introduction - Part I Coordination Compounds Introduction - Part I The majority of compounds studied in the laboratory to date have either been simple ionic salts such as KCl or covalent molecules such as cyclohexane, C 6 H

More information

Acidity and Alkalinity of Drinking Water

Acidity and Alkalinity of Drinking Water Experiment 9 Acidity and Alkalinity of Drinking Water A. Acidity General Discussion While ph is a measure of a water sample's deviation from a neutral value of 7.00, it provides little information about

More information

Separation and Identification of Group B Cations (Bi 3+, Fe 3+, Mn 2+, Cr 3+ and Al 3+ )

Separation and Identification of Group B Cations (Bi 3+, Fe 3+, Mn 2+, Cr 3+ and Al 3+ ) Objectives Name: Separation and Identification of Group B Cations (Bi 3+, Fe 3+, Mn 2+, Cr 3+ and Al 3+ ) To understand the chemical reactions involved in the separation and identification of the Group

More information

Rev 2016-09-23. Experiment 3

Rev 2016-09-23. Experiment 3 Experiment 3 PREPARATION OF A STANDARD SODIUM HYDROXIDE SOLUTION, DETERMINATION OF PURITY OF IMPURE KHP AND STANDARDIZATION OF HYDROCHLORIC ACID 2 lab periods Reading: Chapter 1 (pg 22-24), Chapter 8,

More information

Lab 6 Two Weeks Characterization of Inorganic Compounds*

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

More information

Solution Stoichiometry Quantitative Preparation of Aqueous Solutions

Solution Stoichiometry Quantitative Preparation of Aqueous Solutions Solution Stoichiometry Quantitative Preparation of Aqueous Solutions Introduction Page 1 of 11 In this week s lab, you and your lab partner will apply your prelab calculations to the preparation of aqueous

More information

Hydrogen Peroxide Analysis

Hydrogen Peroxide Analysis elearning 2009 Introduction Hydrogen Peroxide Analysis Consumer Chemistry Publication No. 91253 Hydrogen peroxide is regarded as an environmentally friendly alternative to chlorine for water purification

More information

NCERT. To determine the concentration/molarity of KMnO 4

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)

More information

Coordination Compounds with Copper (II) Prelab (Week 2)

Coordination Compounds with Copper (II) Prelab (Week 2) Coordination Compounds with Copper (II) Prelab (Week 2) Name Total /10 SHOW ALL WORK NO WORK = NO CREDIT 1. What is the purpose of this experiment? 2. Write the generic chemical formula for the coordination

More information

IDENTIFICATION OF AN UNKNOWN ORGANIC COMPOUND Classification Tests

IDENTIFICATION OF AN UNKNOWN ORGANIC COMPOUND Classification Tests IDENTIFICATION OF AN UNKNOWN ORGANIC COMPOUND Classification Tests In this experiment you will attempt to identify an organic unknown from a selected group of compounds from the class of alcohols, aldehydes,

More information

HOW CAN WE DETERMINE THE ACTUAL PERCENTAGE OF H 2 O 2 IN A DRUGSTORE BOTTLE OF HYDROGEN PEROXIDE

HOW CAN WE DETERMINE THE ACTUAL PERCENTAGE OF H 2 O 2 IN A DRUGSTORE BOTTLE OF HYDROGEN PEROXIDE HOW CAN WE DETERMINE THE ACTUAL PERCENTAGE OF H 2 O 2 IN A DRUGSTORE BOTTLE OF HYDROGEN PEROXIDE Introduction Hydrogen peroxide is regarded as an "environmentally friendly" alternative to chlorine for

More information

Section B: Some Essential Background Chemistry

Section B: Some Essential Background Chemistry Section B: Some Essential Background Chemistry Soluble and insoluble salts The importance of knowing whether a salt is soluble or insoluble in water You will remember that acids react with carbonates to

More information

Austin Peay State University Department of Chemistry CHEM 1111. Copper Cycle

Austin Peay State University Department of Chemistry CHEM 1111. Copper Cycle Cautions Nitric acid and sulfuric acid are toxic and oxidizers and may burn your skin. Nitrogen dioxide gas produced is hazardous if inhaled. Sodium hydroxide is toxic and corrosive and will cause burns

More information

Precipitation Titration: Determination of Chloride by the Mohr Method by Dr. Deniz Korkmaz

Precipitation Titration: Determination of Chloride by the Mohr Method by Dr. Deniz Korkmaz Precipitation Titration: Determination of Chloride by the Mohr Method by Dr. Deniz Korkmaz Introduction Titration is a process by which the concentration of an unknown substance in solution is determined

More information

Qualitative Analysis Identification of Some Important Anions and Cations

Qualitative Analysis Identification of Some Important Anions and Cations Qualitative Analysis Identification of Some Important Anions and Cations Qualitative analysis is the testing of a sample of matter to determine its composition. Qualitative analysis, applied by scientists

More information

REDUCTION-OXIDATION TITRATIONS

REDUCTION-OXIDATION TITRATIONS REDUCTIONOXIDATION TITRATIONS A reductionoxidation reaction (Redox reaction) involves the transfer of an electron(s) from species in the reaction to another. Redox reactions allow titrations of analytes

More information

Analysis of Commerical Antacids Containing Calcium Carbonate Prelab (Week 1)

Analysis of Commerical Antacids Containing Calcium Carbonate Prelab (Week 1) Analysis of Commerical Antacids Containing Calcium Carbonate Prelab (Week 1) Name Total /10 SHOW ALL WORK NO WORK = NO CREDIT 1. What is the purpose of this experiment? 2. Show the calculation for determining

More information

Group A Cation Analysis. Inorganic Qualitative Analysis

Group A Cation Analysis. Inorganic Qualitative Analysis Group A Cation Analysis Inorganic Qualitative Analysis Inorganic qualitative analysis is the unambiguous identification of cations (and/or anions) which are present in a given solution. Unique tests for

More information

Determination of calcium by Standardized EDTA Solution

Determination of calcium by Standardized EDTA Solution Determination of calcium by Standardized EDTA Solution Introduction The classic method of determining calcium and other suitable cations is titration with a standardized solution of ethylenediaminetetraacetic

More information

Oxidation-Reduction Reactions

Oxidation-Reduction Reactions 5 Types of Chemical Reactions Lab 5 Oxidation-Reduction Reactions 5 Types of Chemical Reactions Learning Objectives Oxidize an iron compound Perform an oxidation-reduction reaction Observe and record characteristics

More information

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certifi cate of Education Advanced Subsidiary Level and Advanced Level

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certifi cate of Education Advanced Subsidiary Level and Advanced Level *2215958205* UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certifi cate of Education Advanced Subsidiary Level and Advanced Level CHEMISTRY 9701/31 Advanced Practical Skills 1 October/November

More information

Chemistry 12. Determining the Amount of Vitamin C (Ascorbic Acid) in a Sample

Chemistry 12. Determining the Amount of Vitamin C (Ascorbic Acid) in a Sample Chemistry 12 Determining the Amount of Vitamin C (Ascorbic Acid) in a Sample Abstract Redox reactions are involved in a wide variety of techniques for quantitative analysis of chemical substances. The

More information

HYDROGEN PEROXIDE ANALYSIS INTRODUCTION

HYDROGEN PEROXIDE ANALYSIS INTRODUCTION HYDROGEN PEROXIDE ANALYSIS INTRODUCTION Description Students determine the percent of hydrogen peroxide in store-bought hydrogen peroxide by titration with potassium permanganate. The potassium permanganate

More information

Redox Titrations. -the oxidation/reduction reaction between analyte and titrant

Redox Titrations. -the oxidation/reduction reaction between analyte and titrant Redox Titrations -the oxidation/reduction reaction between analyte and titrant -titrants are commonly oxidizing agents, although reducing titrants can be used -the uivalence point is based upon: A ox +

More information

EXPERIMENT 10: TITRATION AND STANDARDIZATION

EXPERIMENT 10: TITRATION AND STANDARDIZATION EXPERIMENT 10: TITRATION AND STANDARDIZATION PURPOSE To determine the molarity of a NaOH solution by titrating it with a standard HCl solution. To determine the molarity of acetic acid in vinegar using

More information

TITRATION OF VITAMIN C

TITRATION OF VITAMIN C TITRATION OF VITAMIN C Introduction: In this lab, we will be performing two different types of titrations on ascorbic acid, more commonly known as Vitamin C. The first will be an acid-base titration in

More information

Chemical Tests for Unknowns

Chemical Tests for Unknowns Chemical Tests for Unknowns Chemical tests have been developed as a means of identifying what functional groups are present in an unknown compound. Since IR and NMR spectroscopy has been developed, they

More information

Standardization of Potassium Permanganate solution with Standard Sodium Oxalate Solution.

Standardization of Potassium Permanganate solution with Standard Sodium Oxalate Solution. Experiment Number: 07 Name of the experiment: Standardization of Potassium Permanganate solution with Standard Sodium Oxalate Solution. Course: Chem-114 Name: Noor Nashid Islam Roll: 0105044 Group: A2

More information

Experiment # 6 Determining the percent composition of a mixture by acid-base

Experiment # 6 Determining the percent composition of a mixture by acid-base Experiment # 6 Determining the percent composition of a mixture by acid-base Objective Determine the percent composition of a mixture of sodium carbonate (Na 2 CO 3 ), sodium bicarbonate (NaHCO 3 ) and

More information

EXPERIMENT 5: CHEMICAL REACTIONS AND EQUATIONS

EXPERIMENT 5: CHEMICAL REACTIONS AND EQUATIONS PURPOSE EXPERIMENT 5: CHEMICAL REACTIONS AND EQUATIONS To perform and observe simple chemical reactions. To identify the products of chemical reactions and write balanced equations for those reactions.

More information

Recovery of Elemental Copper from Copper (II) Nitrate

Recovery of Elemental Copper from Copper (II) Nitrate Recovery of Elemental Copper from Copper (II) Nitrate Objectives: Challenge: Students should be able to - recognize evidence(s) of a chemical change - convert word equations into formula equations - perform

More information

Experiment 9 - Double Displacement Reactions

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

More information

Expt. 4: ANALYSIS FOR SODIUM CARBONATE

Expt. 4: ANALYSIS FOR SODIUM CARBONATE Expt. 4: ANALYSIS FOR SODIUM CARBONATE Introduction In this experiment, a solution of hydrochloric acid is prepared, standardized against pure sodium carbonate, and used to determine the percentage of

More information

A Volumetric Analysis (Redox Titration) of Hypochlorite in Bleach

A Volumetric Analysis (Redox Titration) of Hypochlorite in Bleach CHEM 311L Quantitative Analysis Laboratory Revision 2.3 A Volumetric Analysis (Redox Titration) of Hypochlorite in Bleach In this laboratory exercise, we will determine the concentration of the active

More information

Oxidation-Reduction Reactions

Oxidation-Reduction Reactions Chapter 18 Oxidation-Reduction Reactions Note to teacher: You will notice that there are two different formats for the Sample Problems in the student textbook. Where appropriate, the Sample Problem contains

More information

Chemical Equilibrium

Chemical Equilibrium 1 Chemical Equilibrium Introduction: In many chemical reactions the reactants are not totally converted to products because of a reverse reaction. In reverse reactions, the products react to form the original

More information

THE 50th INTERNATIONAL CHEMISTRY OLYMPIAD. May 2-8, 2016 PRACTICAL EXAMINATION

THE 50th INTERNATIONAL CHEMISTRY OLYMPIAD. May 2-8, 2016 PRACTICAL EXAMINATION THE 50th INTERNATIONAL CHEMISTRY OLYMPIAD May 2-8, 2016 PRACTICAL EXAMINATION Moscow 2016 General directions 1. You will have 15 min to read the exam text and plan your work before the start. It is forbidden

More information

Additional Lecture: TITRATION BASICS

Additional Lecture: TITRATION BASICS Additional Lecture: TITRATION BASICS 1 Definition and Applications Titration is the incremental addition of a reagent solution (called titrant) to the analyte until the reaction is complete Common applications:

More information

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

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

More information

Lab #13: Qualitative Analysis of Cations and Anions

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

More information

Chapter 16: Tests for ions and gases

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

More information

Experiment 8 - Double Displacement Reactions

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

More information

Preparation of frequently used solutions

Preparation of frequently used solutions Preparation of frequently used solutions Content 1. Diluting Concentrated Acids (Last Login: 08/08/2009) 2. Indicators (Last Login: 27/07/2009) 3. Standard Buffer Solutions (Last Login: 27/07/2009) 4.

More information

The technique used to measure the volume of sodium hydroxide solution required to react with the acid solution is called titration.

The technique used to measure the volume of sodium hydroxide solution required to react with the acid solution is called titration. Experiment 12 Chem 110 Lab TITRATION I. INTRODUCTION In this experiment you will be determining the molarity of an unknown acid solution by measuring the volume of a sodium hydroxide solution of known

More information

Analysis of Hydrogen Peroxide A Redox Titration

Analysis of Hydrogen Peroxide A Redox Titration Analysis of Hydrogen Peroxide A Redox Titration Introduction Hydrogen peroxide is regarded as an "environmentally friendly" alternative to chlorine for water purification and wastewater treatment. Because

More information

Chemistry 1B Experiment 16 77

Chemistry 1B Experiment 16 77 Chemistry 1B Experiment 16 77 16 Qualitative Analysis Introduction The purpose of qualitative analysis is to determine what substances are present in detectable amounts in a sample. This experiment has

More information

THREE CHEMICAL REACTIONS

THREE CHEMICAL REACTIONS THREE CHEMICAL REACTIONS 1 NOTE: You are required to view the podcast entitled Decanting and Suction Filtration before coming to lab this week. Go to http://podcast.montgomerycollege.edu/podcast.php?rcdid=172

More information

Standardization of NaOH

Standardization of NaOH EXPERIMENT 18 Prepared by Edward L. Brown, Lee University The student will become familiar with the techniques of titration and the use of a primary standard, Potassium Hydrogen Phthalate (KHP). Buret

More information

Solubility Product Constant, K sp

Solubility Product Constant, K sp Exercise 5 Page 1 Illinois Central College CHEMISTRY 132 Laboratory Section: Name: Solubility Product Constant, K sp Equipment 2-2500 ml burette 2-250 ml beakers 0300 M NaC 2 0200 M AgNO 3 ferric alum

More information

Calcium Analysis by EDTA Titration

Calcium Analysis by EDTA Titration Calcium Analysis by EDTA Titration ne of the factors that establish the quality of a water supply is its degree of hardness. The hardness of water is defined in terms of its content of calcium and magnesium

More information

The Reaction of Calcium Chloride with Carbonate Salts

The Reaction of Calcium Chloride with Carbonate Salts The Reaction of Calcium Chloride with Carbonate Salts PRE-LAB ASSIGNMENT: Reading: Chapter 3 & Chapter 4, sections 1-3 in Brown, LeMay, Bursten, & Murphy. 1. What product(s) might be expected to form when

More information

Experiment 7: Titration of an Antacid

Experiment 7: Titration of an Antacid 1 Experiment 7: Titration of an Antacid Objective: In this experiment, you will standardize a solution of base using the analytical technique known as titration. Using this standardized solution, you will

More information

hij Teacher Resource Bank GCE Chemistry PSA10: A2 Inorganic Chemistry Carry out a redox titration

hij Teacher Resource Bank GCE Chemistry PSA10: A2 Inorganic Chemistry Carry out a redox titration hij Teacher Resource Bank GCE Chemistry : A2 Inorganic Chemistry Copyright 2009 AQA and its licensors. All rights reserved. The Assessment and Qualifications Alliance (AQA) is a company limited by guarantee

More information

EXPERIMENT II. [Cu{(H 2 N) 2 CS} 3 ] + (aq)

EXPERIMENT II. [Cu{(H 2 N) 2 CS} 3 ] + (aq) EXPERIMENT II STABILIZATION OF RARE OXIDATION STATE-TRIS(THIOUREA) COPPER(I) SULFATE When an element can exist in more than one oxidation state in aqueous solution, each oxidation state will have different

More information

H 2 S(aq) + 2 H 2 O(l) S 2- (aq) + 2 H 3 O + (aq)

H 2 S(aq) + 2 H 2 O(l) S 2- (aq) + 2 H 3 O + (aq) Chem 1B Dr. White Saddleback College 1 Experiment 13/14: Separation and Identification of Group II Cations (The Acidic Sulfide Group: Cu 2+, Bi 3+, (Pb 2+ ), Sn 2+, and, Sb 3+ ) Objectives To understand

More information

Titrations. x C A V B V A. n A n B. x C B C A C B. Acid-base titrations:

Titrations. x C A V B V A. n A n B. x C B C A C B. Acid-base titrations: Acid-base titrations: Titrations n A A + n B B products Where: n A moles of acid (A) are neutralised by n B moles of base (B). If we have a solution of known acid but of unknown concentration then we can

More information

You have already seen how precipitation reactions are used in qualitative

You have already seen how precipitation reactions are used in qualitative Chemistry 112 Laboratory: Precipitation of Metal Sulfides Page 17 Precipitation Reactions You have already seen how precipitation reactions are used in qualitative analysis. The separation of the ions

More information

Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent

Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent Water a polar solvent: dissolves most ionic compounds as well as many molecular compounds Aqueous solution:

More information

Chemistry 1215 Experiment #9 Copper and its Compounds

Chemistry 1215 Experiment #9 Copper and its Compounds Chemistry 1215 Experiment #9 Copper and its Compounds Objective The objective of this experiment is to take a piece of copper as efficiently as possible through a series of chemical reactions. The final

More information

EXPERIMENT 7 Reaction Stoichiometry and Percent Yield

EXPERIMENT 7 Reaction Stoichiometry and Percent Yield EXPERIMENT 7 Reaction Stoichiometry and Percent Yield INTRODUCTION Stoichiometry calculations are about calculating the amounts of substances that react and form in a chemical reaction. The word stoichiometry

More information

STOICHIOMETRY: The Reaction of Iron with Copper (II) Sulfate

STOICHIOMETRY: The Reaction of Iron with Copper (II) Sulfate STOICHIOMETRY: The Reaction of Iron with Copper (II) Sulfate Introduction In this experiment we will use stoichiometric principles to deduce the appropriate equation for the reaction between metallic iron

More information

(1) Hydrochloric acid reacts with sodium hypochlorite to form hypochlorous acid: NaOCl(aq) + HCl(aq) HOCl(aq) + NaCl(aq) hypochlorous acid

(1) Hydrochloric acid reacts with sodium hypochlorite to form hypochlorous acid: NaOCl(aq) + HCl(aq) HOCl(aq) + NaCl(aq) hypochlorous acid The Determination of Hypochlorite in Bleach Reading assignment: Chang, Chemistry 10 th edition, pages 156-159. We will study an example of a redox titration in order to determine the concentration of sodium

More information

General Chemistry Lab Experiment 6 Types of Chemical Reaction

General Chemistry Lab Experiment 6 Types of Chemical Reaction General Chemistry Lab Experiment 6 Types of Chemical Reaction Introduction Most ordinary chemical reactions can be classified as one of five basic types. The first type of reaction occurs when two or more

More information

Syllabus OC18 Use litmus or a universal indicator to test a variety of solutions, and classify these as acidic, basic or neutral

Syllabus OC18 Use litmus or a universal indicator to test a variety of solutions, and classify these as acidic, basic or neutral Chemistry: 9. Acids and Bases Please remember to photocopy 4 pages onto one sheet by going A3 A4 and using back to back on the photocopier Syllabus OC18 Use litmus or a universal indicator to test a variety

More information

XI. Methods of Analysis DETERMINATION OF POTASSIUM CARBONATE CALCULATIONS REAGENTS PROCEDURE

XI. Methods of Analysis DETERMINATION OF POTASSIUM CARBONATE CALCULATIONS REAGENTS PROCEDURE XI. NOTE: An automatic titrator may be utilized for ease of analysis, especially if this test is performed often. Contact Technical Service for further information concerning automatic titration. Methods

More information

CHEM 102: Sample Test 5

CHEM 102: Sample Test 5 CHEM 102: Sample Test 5 CHAPTER 17 1. When H 2 SO 4 is dissolved in water, which species would be found in the water at equilibrium in measurable amounts? a. H 2 SO 4 b. H 3 SO + 4 c. HSO 4 d. SO 2 4 e.

More information

Aspirin Synthesis H 3 PO 4

Aspirin Synthesis H 3 PO 4 Aspirin Synthesis Experiment 5 Aspirin is the common name for the compound acetylsalicylic acid, widely used as a fever reducer and as a pain killer. Salicylic acid, whose name comes from Salix, the willow

More information

Lab #10 How much Acetic Acid (%) is in Vinegar?

Lab #10 How much Acetic Acid (%) is in Vinegar? Lab #10 How much Acetic Acid (%) is in Vinegar? SAMPLE CALCULATIONS NEED TO BE DONE BEFORE LAB MEETS!!!! Purpose: You will determine the amount of acetic acid in white vinegar (sold in grocery stores)

More information

Name: AP Chemistry Date: Mr.Grodski III

Name: AP Chemistry Date: Mr.Grodski III Lab 7 Titration of Tums The parietal cells in the stomach secrete hydrochloric acid at a concentration of about 0.155 M (ph normally between 2 and 3). The amount of HCl secreted increases when food enters

More information

HOMEWORK 4A. Definitions. Oxidation-Reduction Reactions. Questions

HOMEWORK 4A. Definitions. Oxidation-Reduction Reactions. Questions HOMEWORK 4A Oxidation-Reduction Reactions 1. Indicate whether a reaction will occur or not in each of following. Wtiring a balcnced equation is not necessary. (a) Magnesium metal is added to hydrochloric

More information

Tutorial 4 SOLUTION STOICHIOMETRY. Solution stoichiometry calculations involve chemical reactions taking place in solution.

Tutorial 4 SOLUTION STOICHIOMETRY. Solution stoichiometry calculations involve chemical reactions taking place in solution. T-27 Tutorial 4 SOLUTION STOICHIOMETRY Solution stoichiometry calculations involve chemical reactions taking place in solution. Of the various methods of expressing solution concentration the most convenient

More information

A Volumetric Analysis (Back-Titration) of the Active Ingredient in an Antacid

A Volumetric Analysis (Back-Titration) of the Active Ingredient in an Antacid CHEM 311L Revision 2.3 A Volumetric Analysis (Back-Titration) of the Active Ingredient in an Antacid In this laboratory exercise, we will determine the amount of weak base present in an Antacid tablet;

More information

C u ( O H ) 2. N i ( N O 3 ) 2. N a m e C a t i o n Cation A n i o n A n i o n

C u ( O H ) 2. N i ( N O 3 ) 2. N a m e C a t i o n Cation A n i o n A n i o n Name Exam 3 Page 1 AQUEUS SLUTINS 1. (8 points) Names, formulas, and water-solubility of compounds. N a m e F o r m u l a Soluble in Water? Ammonium chloride N H 4 C l y e s C u ( H N i ( N 3 Iron(III)

More information

Estimation of Alcohol Content in Wine by Dichromate Oxidation followed by Redox Titration

Estimation of Alcohol Content in Wine by Dichromate Oxidation followed by Redox Titration Sirromet Wines Pty Ltd 850-938 Mount Cotton Rd Mount Cotton Queensland Australia 4165 www.sirromet.com Courtesy of Jessica Ferguson Assistant Winemaker & Chemist Downloaded from seniorchem.com/eei.html

More information

Chemistry Assessment Unit A2 3 Internal Assessment Practical Examination 2

Chemistry Assessment Unit A2 3 Internal Assessment Practical Examination 2 Centre Number 71 Candidate Number ADVANCED General Certificate of Education 2011 Chemistry Assessment Unit A2 3 Internal Assessment Practical Examination 2 [AC232] THURSDAY 19 MAY, MORNING TIME 2 hours

More information

Sample Pretreatment by Digestion

Sample Pretreatment by Digestion Section 4 Sample Pretreatment by Digestion Several procedures require sample digestion before determining total metal content. Digestion uses acid and heat to break organo-metallic bonds and free ions

More information

Number of moles of solute = Concentration (mol. L ) x Volume of solution (litres) or n = C x V

Number of moles of solute = Concentration (mol. L ) x Volume of solution (litres) or n = C x V 44 CALCULATIONS INVOLVING SOLUTIONS INTRODUCTION AND DEFINITIONS Many chemical reactions take place in aqueous (water) solution. Quantities of such solutions are measured as volumes, while the amounts

More information

Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration

Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration GOAL AND OVERVIEW Antacids are bases that react stoichiometrically with acid. The number of moles of acid that

More information

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certifi cate of Education Advanced Subsidiary Level and Advanced Level

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certifi cate of Education Advanced Subsidiary Level and Advanced Level www.xtremepapers.com UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certifi cate of Education Advanced Subsidiary Level and Advanced Level *1417984110* CHEMISTRY 9701/35 Advanced Practical

More information

ANALYSIS OF CALCIUM CARBONATE TABLETS

ANALYSIS OF CALCIUM CARBONATE TABLETS Experiment 9 ANALYSIS OF CALCIUM CARBONATE TABLETS Prepared by Ross S. Nord, Eastern Michigan University PURPOSE To perform a gravimetric exercise to determine weight percent of active ingredient in a

More information

The Bleach Strength Test A Chemical Test Method to Determine the Strength of Sodium Hypochlorite

The Bleach Strength Test A Chemical Test Method to Determine the Strength of Sodium Hypochlorite The Bleach Strength Test A Chemical Test Method to Determine the Strength of Sodium Hypochlorite Background The liquid sodium hypochlorite made by the Continuous Bleach Manufacturing Plant or by other

More information

Non-polar hydrocarbon chain

Non-polar hydrocarbon chain THE SCIENCE OF SOAPS AND DETERGENTS 2000 by David A. Katz. All rights reserved Reproduction permitted for educational purposes as long as the original copyright is included. INTRODUCTION A soap is a salt

More information

STANDARDIZATION OF A SODIUM HYDROXIDE SOLUTION EXPERIMENT 14

STANDARDIZATION OF A SODIUM HYDROXIDE SOLUTION EXPERIMENT 14 STANDARDIZATION OF A SODIUM HYDROXIDE SOLUTION EXPERIMENT 14 OBJECTIVE The objective of this experiment will be the standardization of sodium hydroxide using potassium hydrogen phthalate by the titration

More information

Experiment 12: Qualitative Analysis of Cations

Experiment 12: Qualitative Analysis of Cations 1 Experiment 12: Qualitative Analysis of Cations Pre-Laboratory Assignment The pre-lab assignment for Part A of the experiment is to complete the flow chart and answer the question on page 10 of this document.

More information

ANALYSIS OF WATER FOR CHLORIDE AND SULFATE IONS

ANALYSIS OF WATER FOR CHLORIDE AND SULFATE IONS Test Procedure for ANALYSIS OF WATER FOR CHLORIDE AND SULFATE IONS TxDOT Designation: Tex-619-J Effective Date: August 2005 1. SCOPE 1.1 Use this method to analyze water for chloride and sulfate ions to

More information

EXPERIMENT 12 A SOLUBILITY PRODUCT CONSTANT

EXPERIMENT 12 A SOLUBILITY PRODUCT CONSTANT PURPOSE: 1. To determine experimentally the molar solubility of potassium acid tartrate in water and in a solution of potassium nitrate. 2. To examine the effect of a common ion on the solubility of slightly

More information

CHEMICAL REACTIONS OF COPPER AND PERCENT YIELD KEY

CHEMICAL REACTIONS OF COPPER AND PERCENT YIELD KEY CHEMICAL REACTIONS OF COPPER AND PERCENT YIELD Objective To gain familiarity with basic laboratory procedures, some chemistry of a typical transition element, and the concept of percent yield. Apparatus

More information

Decomposition. Composition

Decomposition. Composition Decomposition 1. Solid ammonium carbonate is heated. 2. Solid calcium carbonate is heated. 3. Solid calcium sulfite is heated in a vacuum. Composition 1. Barium oxide is added to distilled water. 2. Phosphorus

More information

MOLE CONVERSION PROBLEMS. 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles]

MOLE CONVERSION PROBLEMS. 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles] MOLE CONVERSION PROBLEMS 1. What is the molar mass of MgO? [40.31 g/mol] 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles] 3. How many moles are present in 2.5 x 10 23 molecules of CH

More information

EXPERIMENT B7: GREEN CRYSTAL. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to:

EXPERIMENT B7: GREEN CRYSTAL. Learning Outcomes. Introduction. Upon completion of this lab, the student will be able to: 1 EXPERIMENT B7: GREEN CRYSTAL Learning Outcomes Upon completion of this lab, the student will be able to: 1) Synthesize an inorganic salt and purify it using the method of recrystallization. 2) Test the

More information

AN INVESTIGATION OF CHEMICAL REACTIONS II PART I: RELATIVE REACTIVITIES PRE-LAB QUERIES

AN INVESTIGATION OF CHEMICAL REACTIONS II PART I: RELATIVE REACTIVITIES PRE-LAB QUERIES NAME PARTNER(S) SECTION DATE AN INVESTIGATION OF CHEMICAL REACTIONS II This activity explores the reactivity of a number of metals using single replacement reactions and investigates the role of solubility

More information

Chapter 4: Phenomena. Electrolytes. Electrolytes. Molarity & Dilutions. Electrolytes. Chapter 4 Types of Chemical Reactions and Solution Stoichiometry

Chapter 4: Phenomena. Electrolytes. Electrolytes. Molarity & Dilutions. Electrolytes. Chapter 4 Types of Chemical Reactions and Solution Stoichiometry Chapter 4: Phenomena Phenomena: Many different reactions are known to occur. Scientists wondered if these reaction could be separated into groups based on their properties. Look at the reactions below

More information

SYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER

SYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER Chemistry 111 Lab: Synthesis of a Copper Complex Page H-1 SYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER In this experiment you will synthesize a compound by adding NH 3 to a concentrated

More information

Chemical Tests for Alkanes, Alkenes, and Aromatic Compounds

Chemical Tests for Alkanes, Alkenes, and Aromatic Compounds Chemical Tests for Alkanes, Alkenes, and Aromatic Compounds Introduction There are four types of hydrocarbons: alkanes, alkenes, alkynes, and aromatic compounds, each type with different chemical properties.

More information

LABORATORY 6 ION EXCHANGE AND CATION EXCHANGE CAPACITY. Objectives. determine the cation exchange capacity of soils. Introduction

LABORATORY 6 ION EXCHANGE AND CATION EXCHANGE CAPACITY. Objectives. determine the cation exchange capacity of soils. Introduction LABORATORY 6 ION EXCHANGE AND CATION EXCHANGE CAPACITY I Objectives Demonstrate the phenomenon of ion exchange. determine the cation exchange capacity of soils. Learn standard methods used to II Introduction

More information

Western Carolina University. Prelaboratory Exercise Write out the answers on a separate sheet of paper and turn in the paper at the start of lab.

Western Carolina University. Prelaboratory Exercise Write out the answers on a separate sheet of paper and turn in the paper at the start of lab. Name Chemistry 132 Lab 09 Lab Section Chemical Reactions Part II Prelaboratory Exercise Write out the answers on a separate sheet of paper and turn in the paper at the start of lab. 1. Define the terms

More information

Titration of Hydrochloric Acid with Sodium Hydroxide

Titration of Hydrochloric Acid with Sodium Hydroxide Cautions: Hydrochloric acid solution is a strong acid. Sodium hydroxide solution is a strong base. Both are harmful to skin and eyes. Affected areas should be washed thoroughly with copious amounts of

More information

No Brain Too Small. Credits: Four

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

More information